485BPOS

☐ this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

This Post-Effective Amendment No. 462 to the Registration Statement of PIMCO ETF Trust (the “Trust” or the “Registrant”) on Form N-1A (File No. 333-155395) (the “Amendment”) is being filed pursuant to Rule 485(b) under the Securities Act of 1933, as amended, to provide updated financial information for, and to make other non-material changes to, the Trust’s prospectuses and Statement of Additional Information.

PIMCO ETFs

Prospectus

October 31, 2018

Actively Managed Exchange-Traded Funds

	TICKER	EXCHANGE
SHORT DURATION
PIMCO Enhanced Short Maturity Active Exchange-Traded Fund	MINT	NYSE Arca
PIMCO Government Limited Maturity Active Exchange-Traded Fund	GOVY
PIMCO Prime Limited Maturity Active Exchange-Traded Fund	PPRM
CORE
PIMCO Active Bond Exchange-Traded Fund	BOND	NYSE Arca
PIMCO Enhanced Low Duration Active Exchange-Traded Fund	LDUR	NYSE Arca
TAX-EXEMPT MUNICIPAL
PIMCO Short Term Municipal Bond Active Exchange-Traded Fund	SMMU	NYSE Arca
PIMCO Intermediate Municipal Bond Active Exchange-Traded Fund	MUNI	NYSE Arca

Neither the U.S. Securities and Exchange Commission nor the U.S. Commodity Futures Trading Commission has approved or disapproved these securities, or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The Fund seeks current income and long-term capital appreciation, consistent with prudent investment management.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

1 "Other Expenses" include interest expense of 0.21%. Interest expense is borne by the Fund separately from the management fees paid to Pacific Investment Management Company LLC ("PIMCO"). Excluding interest expense, Total Annual Fund Operating Expenses are 0.55%.

Example. The Example is intended to help you compare the cost of investing in the Fund with the costs of investing in other exchange-traded funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Investors may pay brokerage commissions on their purchases and sales of Fund shares, which are not reflected in the Example. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

The Fund pays transaction costs when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example tables, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 142% of the average value of its portfolio.

The Fund invests under normal circumstances at least 80% of its assets in a diversified portfolio of Fixed Income Instruments of varying maturities, which may be represented by forwards or derivatives such as options, futures contracts, or swap agreements. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The Fund will seek to maintain a fairly consistent level of dividend income, subject to market conditions, by investing in a broad array of fixed income sectors and utilizing income efficient implementation strategies. Long-term capital appreciation sought by the Fund generally arises from decreases in interest rates or improving credit fundamentals for a particular sector or security.

The Fund generally seeks to manage capital gain distributions by, among other things, limiting portfolio turnover and attempting to use losses from sales of securities that have declined in price to offset gains that would otherwise be taxable. However, such strategy may be unsuccessful or only partially successful and the Fund may realize taxable gains. For example, the Fund may realize taxable gains in order to satisfy cash redemption requests or when PIMCO believes the benefits of a transaction resulting in the realization of taxable gains outweigh tax considerations.

In pursuing the Fund's investment objective, PIMCO may emphasize investment strategies that are more strategic, or long-term in nature, with less emphasis on short-term, tactical trading strategies. In addition, PIMCO will utilize a bottom up approach to seek to identify asset classes and securities that are undervalued, and the Fund's investment program may involve a longer investment horizon designed to minimize trading volume and distinct investment strategies as compared with other PIMCO-advised funds with names, investment objectives and policies similar to the Fund. As a result, investments made by the Fund and the results achieved by the Fund at any given time are not expected to be the same as or similar to those made by such other PIMCO-advised funds.

The average portfolio duration of this Fund normally varies from two to eight years based on PIMCO's market forecasts. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates.

The Fund invests primarily in investment grade debt securities, but may invest up to 30% of its total assets in high yield securities ("junk bonds"), as rated by Moody's Investors Service, Inc. ("Moody's"), Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, as determined by PIMCO. The Fund may invest up to 15% of its total assets in securities denominated in foreign currencies, and may invest beyond this limit in U.S. dollar-denominated securities of foreign issuers. The Fund may invest up to 15% of its total assets in securities and instruments that are economically tied to emerging market countries. The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 10% of its total assets.

The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs or dollar rolls).

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Market Trading Risk: the risk that an active secondary trading market for Fund shares does not continue once developed, that the Fund may not continue to meet a listing exchange's trading or listing requirements, or that Fund shares trade at prices other than the Fund's net asset value

Interest Rate Risk: the risk that fixed income securities will decline in value because of an increase in interest rates; a fund with a longer average portfolio duration will be more sensitive to changes in interest rates than a fund with a shorter average portfolio duration

Call Risk: the risk that an issuer may exercise its right to redeem a fixed income security earlier than expected (a call). Issuers may call outstanding securities prior to their maturity for a number of reasons (e.g., declining interest rates, changes in credit spreads and improvements in the issuer's credit quality). If an issuer calls a security that the Fund has invested in, the Fund may not recoup the full amount of its initial investment and may be forced to reinvest in lower-yielding securities, securities with greater credit risks or securities with other, less favorable features

Credit Risk: the risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to a derivative contract, is unable or unwilling to meet its financial obligations

High Yield Risk: the risk that high yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit, call and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments, and may be more volatile than higher-rated securities of similar maturity

Market Risk: the risk that the value of securities owned by the Fund may go up or down, sometimes rapidly or unpredictably, due to factors affecting securities markets generally or particular industries

Issuer Risk: the risk that the value of a security may decline for a reason directly related to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods or services

Liquidity Risk: the risk that a particular investment may be difficult to purchase or sell and that the Fund may be unable to sell illiquid securities at an advantageous time or price or achieve its desired level of exposure to a certain sector. Liquidity risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund's use of derivatives may result in losses to the Fund, a reduction in the Fund's returns and/or increased volatility. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction. Changes in regulation relating to a fund's use of derivatives and related instruments could potentially limit or impact the Fund's ability to invest in derivatives, limit the Fund's ability to employ certain strategies that use derivatives and/ or adversely affect the value of derivatives and the Fund's performance

Equity Risk: the risk that the value of equity or equity-related securities may decline due to general market conditions which are not specifically related to a particular company or to factors affecting a particular industry or industries. Equity or equity-related securities generally have greater price volatility than fixed income securities

Mortgage-Related and Other Asset-Backed Securities Risk: the risks of investing in mortgage-related and other asset-backed securities, including interest rate risk, extension risk, prepayment risk, and credit risk

Foreign (Non-U.S.) Investment Risk: the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to smaller markets, differing reporting, accounting and auditing standards, increased risk of delayed settlement of portfolio transactions or loss of certificates of portfolio securities, and the risk of unfavorable foreign government actions, including nationalization, expropriation or confiscatory taxation, currency blockage, or political changes or diplomatic developments. Foreign securities may also be less liquid and more difficult to value than securities of U.S. issuers

Emerging Markets Risk: the risk of investing in emerging market securities, primarily increased foreign (non-U.S.) investment risk

Currency Risk: the risk that foreign (non-U.S.) currencies will change in value relative to the U.S. dollar and affect the Fund's investments in foreign (non-U.S.) currencies or in securities that trade in, and receive revenues in, or in derivatives that provide exposure to, foreign (non-U.S.) currencies

Leveraging Risk: the risk that certain transactions of the Fund, such as reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions, or derivative instruments, may give rise to leverage, magnifying gains and losses and causing the Fund to be more volatile than if it had not been leveraged. This means that leverage entails a heightened risk of loss

Management Risk: the risk that the investment techniques and risk analyses applied by PIMCO will not produce the desired results and that legislative, regulatory, or tax restrictions, policies or developments may affect the investment techniques available to PIMCO and the individual portfolio manager in connection with managing the Fund. There is no guarantee that the investment objective of the Fund will be achieved

Short Exposure Risk: the risk of entering into short sales, including the potential loss of more money than the actual cost of the investment, and the risk that the third party to the short sale will not fulfill its contractual obligations, causing a loss to the Fund

Convertible Securities Risk: as convertible securities share both fixed income and equity characteristics, they are subject to risks to which fixed income and equity investments are subject. These risks include equity risk, interest rate risk and credit risk

Tax-Efficient Investing Risk: the risk that investment strategies intended to manage capital gain distributions may not succeed, and that such strategies may reduce investment returns or result in investment losses

Distribution Rate Risk: the risk that the Fund's distribution rate may change unexpectedly as a result of numerous factors, including changes in realized and projected market returns, fluctuations in market interest rates, Fund performance and other factors

Please see "Description of Principal Risks" in the Fund's prospectus for a more detailed description of the risks of investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The performance information shows summary performance information for the Fund in a bar chart and an Average Annual Total Returns table. The information provides some indication of the risks of investing in the Fund by showing changes in its performance from year to year and by showing how the Fund's average annual returns compare with the returns of a broad-based securities market index. Absent any applicable fee waivers and/or expense limitations, if any, performance would have been lower. The Fund's past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

The Bloomberg Barclays U.S. Aggregate Index represents securities that are SEC-registered, taxable, and dollar denominated. The index covers the U.S. investment grade fixed rate bond market, with index components for government and corporate securities, mortgage pass-through securities, and asset-backed securities. These major sectors are subdivided into more specific indexes that are calculated and reported on a regular basis.

Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is -1.09%. For the periods shown in the bar chart, the highest quarterly return was 2.73% in the Q1 2015, and the lowest quarterly return was -3.08% in the Q2 2013.

1 After-tax returns are calculated using the highest historical individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. In some cases the return after taxes may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

PIMCO serves as the investment adviser for the Fund. The Fund's portfolio is jointly and primarily managed by David Braun, Jerome Schneider and Daniel Hyman. Messrs. Braun, Schneider and Hyman are Managing Directors of PIMCO, and they have managed the Fund since May 2017.

For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial intermediaries, please turn to the "Summary of Other Important Information Regarding Fund Shares" section on page 19 of this prospectus.

The Fund seeks maximum total return, consistent with preservation of capital and prudent investment management.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

1 "Other Expenses" include interest expense of 0.63%. Interest expense is borne by the Fund separately from the management fees paid to Pacific Investment Management Company LLC ("PIMCO"). Excluding interest expense, Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement are 0.39%.

2 PIMCO has contractually agreed, through October 31, 2019, to reduce its management fee by 0.07% of the average daily net assets of the Fund. This Fee Limitation Agreement renews annually unless terminated by PIMCO upon at least 30 days' prior notice to the end of the contract term. Under certain conditions, PIMCO may recoup amounts reduced in future periods, not exceeding three years.

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its net assets in a diversified portfolio of Fixed Income Instruments of varying maturities, which may be represented by forwards or derivatives such as options, futures contracts, or swap agreements. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The average portfolio duration of this Fund normally varies from one to three years based on PIMCO's market forecasts. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates. The Fund will seek to maintain a fairly consistent level of dividend income, subject to market conditions, by investing in a broad array of fixed income sectors and utilizing income efficient implementation strategies.

The Fund invests primarily in investment grade debt securities, but may invest up to 15% of its total assets in high yield securities ("junk bonds"), as rated by Moody's Investors Service, Inc. ("Moody's"), Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, as determined by PIMCO. The Fund may invest, without limitation, in U.S. dollar denominated securities and instruments of foreign issuers. The Fund will normally limit its foreign currency exposure (such as from non-U.S. dollar-denominated currencies) to 5% of its total assets. The Fund may invest up to 10% of its total assets in securities and instruments that are economically tied to emerging market countries.

The Fund may invest, without limitation, in derivative instruments, such as options, futures contracts or swap agreements, or in mortgage- or asset-backed securities, subject to applicable law and any other restrictions described in the Fund's prospectus or Statement of Additional Information. The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis and may engage in short sales. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs or dollar rolls). The "total return" sought by the Fund consists of income earned on the Fund's investments, plus capital appreciation, if any, which generally arises from decreases in interest rates, foreign currency

appreciation, or improving credit fundamentals for a particular sector or security.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

New/Small Fund Risk: the risk that a new or smaller fund's performance may not represent how the fund is expected to or may perform in the long term. In addition, new funds have limited operating histories for investors to evaluate and new and smaller funds may not attract sufficient assets to achieve investment and trading efficiencies

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund's use of derivatives may result in losses to the Fund, a reduction in the Fund's returns and/or increased volatility. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction. Changes in regulation relating to a fund's use of derivatives and related instruments could potentially limit or impact the Fund's ability to invest in derivatives, limit the Fund's ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund's performance

Emerging Markets Risk: the risk of investing in emerging market securities, primarily increased foreign (non-U.S.) investment risk

portfolio manager in connection with managing the Fund. There is no guarantee that the investment objective of the Fund will be achieved

The ICE BofAML 1-3 Year U.S. Treasury Index is an unmanaged index comprised of U.S. Treasury securities, other than inflation-protection securities and Separate Trading of Registered Interest and Principal of Securities, with at least $1 billion in outstanding face value and a remaining term to final maturity of at least one year and less than three years.

Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is 1.10%. For the periods shown in the bar chart, the highest quarterly return was 1.39% in the Q1 2015, and the lowest quarterly return was -0.58% in the Q3 2015.

PIMCO serves as the investment adviser for the Fund. The Fund's portfolio is jointly and primarily managed by David Braun, Jerome Schneider and Hozef Arif. Messrs. Braun and Schneider are Managing Directors of PIMCO. Mr. Arif is an Executive Vice President of PIMCO. Mr. Schneider has managed the Fund since January 2014. Messrs. Braun and Arif have managed the Fund since May 2017.

The Fund seeks maximum current income, consistent with preservation of capital and daily liquidity.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

1 "Other Expenses" include interest expense of 0.07%. Interest expense is borne by the Fund separately from the management fees paid to Pacific Investment Management Company LLC ("PIMCO"). Excluding interest expense, Total Annual Fund Operating Expenses are 0.35%.

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its net assets in a diversified portfolio of Fixed Income Instruments of varying maturities, which may be represented by forwards. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The average portfolio duration of this Fund will vary based on PIMCO's market forecasts and will normally not exceed one year. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates. The dollar-weighted average portfolio maturity of the Fund is normally not expected to exceed three years.

The Fund primarily invests in U.S. dollar-denominated investment grade debt securities, rated Baa or higher by Moody's Investors Service, Inc. ("Moody's"), or equivalently rated by Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, determined by PIMCO to be of comparable quality. The Fund may invest, without limitation, in U.S. dollar-denominated securities and instruments of foreign issuers.

The Fund may invest, without limitation, in mortgage or asset-backed securities, including to-be-announced transactions. The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs or dollar rolls).

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Credit Risk: the risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to a forward commitment transaction, is unable or unwilling to meet its financial obligations

reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity

Leveraging Risk: the risk that certain transactions of the Fund, such as reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions may give rise to leverage, magnifying gains and losses and causing the Fund to be more volatile than if it had not been leveraged. This means that leverage entails a heightened risk of loss

The FTSE 3-Month Treasury Bill Index is an unmanaged index representing monthly return equivalents of yield averages of the last 3 month Treasury Bill issues. The Fund began operations on 11/16/09. Index comparisons began on 11/30/09.

Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is 1.49%. For the periods shown in the bar chart, the highest quarterly return was 1.24% in the Q1 2012, and the lowest quarterly return was -0.57% in the Q3 2011.

PIMCO serves as the investment adviser for the Fund. The Fund's portfolio is managed by Jerome Schneider. Mr. Schneider is a Managing Director of PIMCO, and he has managed the Fund since its inception in November 2009.

The Fund seeks maximum current income, consistent with preservation of capital and daily liquidity.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

1 "Other Expenses" reflect estimated organizational expenses for the Fund's first fiscal year.

2 Pacific Investment Management Company LLC ("PIMCO") has contractually agreed, through October 31, 2019, to waive its management fee, or reimburse the Fund, to the extent that organizational expenses and pro rata Trustees' fees exceed 0.0049% of the Fund's average net assets (the "Expense Limit"). Under the Expense Limitation Agreement, which renews annually for a full year unless terminated by PIMCO upon at least 30 days' notice prior to the end of the contract term, PIMCO may recoup these waivers and reimbursements in future periods, not exceeding three years, provided that organizational expenses and pro rata Trustees' fees, plus recoupment, do not exceed the Expense Limit.

3 To maintain certain net yields for the Fund, PIMCO or its affiliates may temporarily and voluntarily waive, reduce or reimburse all or any portion of the Fund's fees and expenses. Such waivers, if any, are not reflected in this table. See "Management of the Funds—Temporary Fee Waivers, Reductions and Reimbursements" in the Fund's prospectus for additional information.

The Fund pays transaction costs when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example tables, affect the Fund's performance. The Fund had not yet commenced operations as of the most recent fiscal year end. Thus, no portfolio turnover rate is provided for the Fund.

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its assets in a diversified portfolio of fixed income securities that are issued or guaranteed by the U.S. Government, its agencies or government-sponsored enterprises ("U.S. Government Securities"). Assets not invested in U.S. Government Securities may be invested in other types of Fixed Income Instruments. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities.

The Fund's investments in Fixed Income Instruments are limited to those of investment grade U.S. dollar-denominated securities of U.S. issuers that are rated Aa or higher by Moody's Investors Service, Inc. ("Moody's"), or equivalently rated by Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, determined by PIMCO to be of comparable quality. The average portfolio duration of this Fund will vary based on PIMCO's market forecasts and will normally not exceed one year. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates. The Fund may only invest in securities that mature within three years from the date of purchase.

The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs or dollar rolls).

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

New/Small Fund Risk: the risk that a new or smaller fund's performance may not represent how the fund is expected to or may perform in the long term. In addition, new funds have limited operating histories for investors to evaluate and new and smaller funds may not attract sufficient assets to achieve investment and trading efficiencies

Fund may not recoup the full amount of its initial investment and may be forced to reinvest in lower-yielding securities, securities with greater credit risks or securities with other, less favorable features

Leveraging Risk: the risk that certain transactions of the Fund, such as reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions may give rise to leverage, magnifying gains and losses and causing the Fund to be more volatile than if it had not been leveraged. This means that leverage entails a heightened risk of loss

The Fund does not have a full calendar year of performance. Thus, no bar chart or Average Annual Total Returns table is included for the Fund. Once the Fund commences operations, performance will be updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

PIMCO serves as the investment adviser for the Fund. The Fund 's portfolio is managed by Jerome Schneider. Mr. Schneider is a Managing Director of PIMCO and he will manage the Fund as of its inception.

The Fund seeks attractive tax-exempt income, consistent with preservation of capital.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its assets in a diversified portfolio of debt securities whose interest is, in the opinion of bond counsel for the issuer at the time of issuance, exempt from federal income tax ("Municipal Bonds"). Municipal Bonds generally are issued by or on behalf of states and local governments and their agencies, authorities and other instrumentalities.

The Fund does not intend to invest in Municipal Bonds whose interest is subject to the federal alternative minimum tax. The Fund may only invest in U.S. dollar-denominated investment grade debt securities, rated Baa or higher by Moody's Investors Service, Inc. ("Moody's"), or equivalently rated by Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, determined by Pacific Investment Management Company LLC ("PIMCO") to be of comparable quality. The Fund may invest 25% or more of its total assets in Municipal Bonds that finance similar projects, such as those relating to education, health care, housing, transportation, and utilities, and 25% or more of its total assets in industrial development bonds. The average portfolio duration of this Fund normally varies within (negative) 2 years to positive 4 years of the portfolio duration of the securities comprising the Bloomberg Barclays 1-15 Year Municipal Bond Index, as calculated by PIMCO, which, as of September 30, 2018, was 5.09 years. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates. The portfolio manager focuses on bonds with the potential to offer attractive current income, typically looking for bonds that can provide consistently attractive current yields or that are trading at competitive market prices.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Municipal Bond Risk: the risk that by investing in Municipal Bonds the Fund may be affected significantly by the economic, regulatory or political developments affecting the ability of issuers of Municipal Bonds to pay interest or repay principal

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund's use of derivatives may result in losses to the Fund, a reduction in the Fund's returns and/or increased volatility. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction. Changes in regulation relating to a fund's use of derivatives and related instruments could potentially limit or impact the Fund's ability to invest in derivatives, limit the Fund's ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund's performance

California State-Specific Risk: the risk that by concentrating its investments in California Municipal Bonds, the Fund may be affected significantly by economic, regulatory or political developments affecting the ability of California issuers to pay interest or repay principal

New York State-Specific Risk: the risk that by concentrating its investments in New York Municipal Bonds, the Fund may be affected significantly by economic, regulatory or political developments affecting the ability of New York issuers to pay interest or repay principal

Municipal Project-Specific Risk: the risk that the Fund may be more sensitive to adverse economic, business or political developments if it invests a substantial portion of its assets in the bonds of similar projects (such as those relating to education, health care, housing, transportation, and utilities), industrial development bonds, or in bonds from issuers in a single state

The Bloomberg Barclays 1-15 Year Municipal Bond Index consists of a broad selection of investment grade general obligation and revenue bonds of maturities ranging from one year to 17 years. It is an unmanaged index representative of the tax exempt bond market.

Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is -0.28%. For the periods shown in the bar chart, the highest quarterly return was 3.49% in the Q3 2010, and the lowest quarterly return was -3.65% in the Q4 2016.

PIMCO serves as the investment adviser for the Fund. The Fund's portfolio is jointly and primarily managed by Julie Callahan and David Hammer. Ms. Callahan is a Senior Vice President of PIMCO, and she has managed the Fund since August 2015. Mr. Hammer is an Executive Vice President of PIMCO, and he has managed the Fund since June 2016.

The Fund seeks maximum current income, consistent with preservation of capital and daily liquidity.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

1 "Other Expenses" reflect estimated organizational expenses for the Fund's first fiscal year.

The Fund pays transaction costs when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example tables, affect the Fund's performance. The Fund had not yet commenced operations as of the most recent fiscal year end. Thus, no portfolio turnover rate is provided for the Fund.

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 65% of its total assets in a diversified portfolio of fixed income securities of varying maturities. The Fund may only invest in U.S. dollar denominated securities that mature within 18 months from the date of purchase or floating rate U.S. government agency securities that mature within two years from the date of purchase. The average portfolio duration of this Fund will vary based on PIMCO's market forecasts and will normally not exceed 90 days. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates.

The Fund primarily invests in U.S. dollar-denominated investment grade debt securities, rated A or higher by Moody's Investors Service, Inc. ("Moody's"), or equivalently rated by Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, determined by PIMCO to be of comparable quality.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Leveraging Risk: the risk that certain transactions of the Fund, such as reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions may give rise to leverage, magnifying gains and losses and causing the Fund to be more volatile than if it had not been leveraged. This means that leverage entails a heightened risk of loss

The Fund seeks attractive tax-exempt income, consistent with preservation of capital.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund does not intend to invest in Municipal Bonds whose interest is subject to the federal alternative minimum tax. The Fund may only invest in U.S. dollar-denominated investment grade debt securities, rated Baa or higher by Moody's Investors Service, Inc. ("Moody's"), or equivalently rated by Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, determined by Pacific Investment Management Company LLC ("PIMCO") to be of comparable quality. The Fund may invest 25% or more of its total assets in Municipal Bonds that finance similar projects, such as those relating to education, health care, housing, transportation, and utilities, and 25% or more of its total assets in industrial development bonds. The average portfolio duration of this Fund varies based on PIMCO's market forecasts and under normal market conditions is not expected to exceed three years. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates. The dollar-weighted average portfolio maturity of the Fund is normally not expected to exceed three years. The portfolio manager focuses on bonds with the potential to offer attractive current income, typically looking for bonds that can provide consistently attractive current yields or that are trading at competitive market prices.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund's use of derivatives may result in losses to the Fund, a reduction in the Fund's returns and/or increased volatility. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction. Changes in regulation relating to a fund's use of derivatives and related instruments could potentially limit or impact the Fund's ability to invest in derivatives, limit the Fund's ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund's performance

The Bloomberg Barclays 1 Year Municipal Bond Index is the 1 Year (1-2) component of the Bloomberg Barclays Municipal Bond Index. The Bloomberg Barclays Municipal Bond Index is a rules-based, market-value-weighted index engineered for the long term tax-exempt bond market. To be included in the Index, bonds must be rated investment-grade (Baa3/BBB- or higher) by at least two of the following ratings agencies: Moody's, S&P and Fitch. If only two of the three agencies rate the security, the lower rating is used to determine index eligibility. If only one of the three agencies rates a security, the rating must be investment-grade. They must have an outstanding par value of at least $7 million and be issued as part of a transaction of at least $75 million. The bonds must be fixed rate, have a dated-date after December 31, 1990, and must be at least one year from their maturity date. Remarketed issues, taxable municipal bonds, bonds with floating rates, and derivatives, are excluded from the benchmark. It is not possible to invest directly in an index.

Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is 0.58%. For the periods shown in the bar chart, the highest quarterly return was 1.13% in the Q1 2017, and the lowest quarterly return was -1.22% in the Q4 2016.

PIMCO serves as the investment adviser for the Fund. The Fund's portfolio is jointly and primarily managed by Julie Callahan and David Hammer. Ms. Callahan is a Senior Vice President of PIMCO, and she has managed the Fund since January 2014. Mr. Hammer is an Executive Vice President of PIMCO, and he has managed the Fund since August 2015.

Each Fund is an exchange-traded fund ("ETF"). Individual Fund shares may only be purchased and sold on a national securities exchange through a broker-dealer and may not be purchased or redeemed directly with a Fund. The price of Fund shares is based on market price, and because ETF shares trade at market prices rather than net asset value ("NAV"), shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). The Funds will only issue or redeem shares at NAV that have been aggregated into blocks of 20,000 shares (PIMCO Enhanced Low Duration Active Exchange-Traded Fund), 50,000 shares (PIMCO Active Bond Exchange-Traded, PIMCO Intermediate Municipal Bond Active Exchange-Traded and PIMCO Short Term Municipal Bond Active Exchange-Traded Funds), 70,000 shares (PIMCO Enhanced Short Maturity Active Exchange-Traded Funds) or 90,000 shares (PIMCO Government Limited Maturity Active Exchange-Traded and PIMCO Prime Limited Maturity Active Exchange-Traded Fund) or multiples thereof ("Creation Units") with certain large institutional investors who have entered into agreements with the Funds' Distributor ("Authorized Participants"). A Fund will issue or redeem Creation Units in return for a basket of cash and/or securities that the Fund specifies each Business Day.

The Funds' taxable distributions are generally taxable to you as ordinary income, capital gains, or a combination of the two, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account, in which case distributions may be taxable upon withdrawal.

Dividends paid to shareholders of the PIMCO Short Term Municipal Bond Active Exchange-Traded Fund and PIMCO Intermediate Municipal Bond Active Exchange-Traded Fund derived from interest from debt securities whose interest is, in the opinion of bond counsel for the issuer at the time of issuance, exempt from federal income tax ("Municipal Bonds") are expected to be designated by the Funds as "exempt-interest dividends" and shareholders may generally exclude such dividends from gross income for federal income tax purposes.

If you purchase Fund shares through a broker-dealer or other financial intermediary, PIMCO or other related companies may pay the intermediary for the sale of Fund shares or related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend a Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

This prospectus describes eight ETFs (each a "Fund," collectively, the "Funds") offered by PIMCO ETF Trust (the "Trust"). The Funds provide access to the professional investment advisory services offered by PIMCO. References to "the Fund" or "a Fund" relate to all Funds unless the context requires otherwise.

ETFs are funds that trade like other publicly-traded securities and may be designed to track an index or to be actively managed. Unlike conventional ETFs, the Funds are not index funds. The Funds are actively managed and do not seek to replicate the performance of a specified index. Unlike shares of a mutual fund, which can be bought from and redeemed by the issuing fund by all shareholders at a price based on NAV, shares of a Fund may be directly purchased from and redeemed by the Fund at NAV solely by Authorized Participants. Also unlike shares of a mutual fund, shares of a Fund are listed on a national securities exchange and trade in the secondary market at market prices that change throughout the day.

Once operational, shares of a Fund are listed and traded at market prices on NYSE Arca, Inc. ("NYSE Arca") and other secondary markets. The market price for a Fund's shares may be different from the Fund's NAV. The Funds issue and redeem shares at NAV only in Creation Units. Only Authorized Participants may purchase or redeem Creation Units directly with a Fund at NAV. These transactions are in exchange for cash and/or securities. Except when aggregated in Creation Units, shares of a Fund are not redeemable securities. Shareholders who are not Authorized Participants may not purchase or redeem shares directly from a Fund.

If a Fund were to effect redemptions with an Authorized Participant primarily for cash, the Fund may be required to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. The sale of portfolio securities could cause a Fund to recognize gains that it might not otherwise have recognized if redemptions were effected in-kind, or to recognize such gain sooner than would otherwise be required. Such gains will generally be distributed to shareholders to avoid taxation at the Fund level and to ensure compliance with other special tax rules that apply to the Funds. Moreover, the sale of portfolio securities will generally subject the Funds to transaction costs, which may be partially or totally offset by the variable transaction fee charged by the Funds to redeeming Authorized Participants.

An investment in a particular Fund alone should not constitute an entire investment program. This prospectus explains what you should know about the Funds before you invest. Please read it carefully. Certain affiliates of the Funds and PIMCO may purchase and resell Fund shares pursuant to this prospectus.

On each business day, before commencement of trading on NYSE Arca, each Fund will disclose on www.pimcoetfs.com the identities and quantities of the Fund's portfolio holdings that will form the basis for the Fund's calculation of NAV at the end of the business day. Fund fact sheets provide additional information regarding the Funds and may be requested by calling 1.888.400.4ETF (1.888.400.4383).

The value of your investment in a Fund changes with the market price of the Fund's shares determined in the secondary market. Market price may be determined, in part, by the values of a Fund's investments. Many factors can affect those values. The factors that are most likely to have a material effect on a particular Fund's portfolio as a whole are called "principal risks." The principal risks of each Fund are identified in the Fund Summaries. The principal risks are described in this section. Each Fund may be subject to additional risks other than those identified and described below because the types of investments made by a Fund can change over time. Securities and investment techniques mentioned in this summary that appear in bold type are described in greater detail under "Characteristics and Risks of Securities and Investment Techniques." That section and "Investment Objectives and Policies" in the Statement of Additional Information (the "SAI") also include more information about the Funds, their investments and the related risks. There is no guarantee that a Fund will be able to achieve its investment objective. It is possible to lose money by investing in a Fund.

A new or smaller Fund's performance may not represent how the Fund is expected to or may perform in the long term if and when it becomes larger and has fully implemented its investment strategies. Investment positions may have a disproportionate impact (negative or positive) on performance in new and smaller Funds. New and smaller Funds may also require a period of time before they are fully invested in securities that meet their investment objectives and policies and achieve a representative portfolio composition. Fund performance may be lower or higher during this "ramp-up" period, and may also be more volatile, than would be the case after the Fund is fully invested. Similarly, a new or smaller Fund's investment strategy may require a longer period of time to show returns that are representative of the strategy. New Funds have limited performance histories for investors to evaluate and new and smaller Funds may not attract sufficient assets to achieve investment and trading efficiencies. If a new or smaller Fund were to fail to successfully implement its investment strategies or achieve its investment objective, performance may be negatively impacted, and any resulting liquidation could create negative transaction costs for the Fund and tax consequences for investors.

Each Fund is subject to secondary market trading risks. Once operational, shares of a Fund are listed for trading on an exchange, however, there can be no guarantee that an active trading market for such shares will develop or continue. Shares of a Fund may be listed or traded on U.S. and foreign (non-U.S.) exchanges other than the Fund's primary U.S. listing exchange. There can be no guarantee that a Fund's shares will continue trading on any exchange or in any market or that the Fund's shares will continue to meet the listing or trading requirements of any exchange or market. A Fund's shares may experience higher trading volumes on one exchange as compared to another and investors are subject to the execution and settlement risks of the market where their broker directs trades.

Secondary market trading in a Fund's shares may be halted by an exchange because of market conditions. Pursuant to exchange or market rules, trading in a Fund's shares on an exchange or in any market may be subject to trading halts caused by extraordinary market volatility. If secondary market trading is halted or an exchange closes earlier than anticipated, you may be unable to purchase or sell Fund shares. There can be no guarantee that a Fund's exchange listing or ability to trade its shares will continue or remain unchanged. In the event a Fund ceases to be listed on an exchange, the Fund may cease operating as an "exchange-traded" fund and operate as a mutual fund, provided that shareholders are given advance notice.

Buying or selling a Fund's shares on an exchange may require the payment of brokerage commissions. In addition, you may also incur the cost of the spread (the difference between the bid price and the ask price). The commission is frequently a fixed amount and may be a significant cost for investors seeking to buy or sell small amounts of shares. The spread varies over time for shares of a Fund based on their trading volume and market liquidity, and is generally less if the Fund has more trading volume and market liquidity and more if the Fund has less trading volume and market liquidity. Due to the costs inherent in buying or selling a Fund's shares, frequent trading may detract significantly from investment returns. Investment in a Fund's shares may not be advisable for investors who expect to engage in frequent trading.

Shares of a Fund may trade on an exchange at prices at, above or below their most recent NAV. The market prices of Fund shares will fluctuate, sometimes rapidly and materially, in response to changes in the Fund's NAV, the value of Fund holdings and supply and demand for Fund shares. Although the creation/redemption feature of the Funds generally makes it more likely that Fund shares will trade close to NAV, market volatility, lack of an active trading market for Fund shares, disruptions at market participants (such as Authorized Participants or market makers) and any disruptions in the ordinary functioning of the creation/redemption process may result in Fund shares trading significantly above (at a "premium") or below (at a "discount") NAV. Additionally, to the extent a Fund holds securities traded in markets that close at a different time from the Fund's listing exchange, liquidity in such securities may be reduced after the applicable closing times, and during the time when the Fund's listing exchange is open but after the applicable market closing, fixing or settlement times, bid/ask spreads and the resulting premium or discount to the Fund's shares' NAV may widen. You may be unable to sell your shares or may incur significant losses if you transact in Fund shares in these and other circumstances. Neither PIMCO nor the Trust can predict whether Fund shares will trade above, below or at NAV. A Fund's investment results are based on the Fund's daily NAV. Investors transacting in Fund shares in the secondary market, where market prices may differ from NAV, may experience investment results that differ from results based on the Fund's daily NAV. There are various methods by which investors can purchase and sell shares and various orders that may be placed. Investors should consult their financial intermediary before purchasing or selling shares of the Funds.

A Fund has a limited number of intermediaries that act as Authorized Participants, and none of these Authorized Participants are or will be obligated to engage in creation or redemption transactions. To the extent that these intermediaries exit the business or are unable to or choose not to proceed with creation and/or redemption orders with respect to a Fund and no other Authorized Participant is able and willing to create or redeem,

shares may trade at a discount to NAV and possibly face trading halts and/ or delisting. Additionally, while Fund shares are listed for trading on an exchange, there can be no assurance that active trading markets for Fund shares will be maintained by market makers or Authorized Participants. Decisions by market makers or Authorized Participants to reduce their role or "step away" from these activities in times of market stress may inhibit the effectiveness of the creation/redemption process in maintaining the relationship between the underlying value of a Fund's holdings and the Fund's NAV. Such reduced effectiveness could result in the Fund's shares trading at a discount to its NAV and also in greater than normal intraday bid/ask spreads for the Fund's shares.

Interest rate risk is the risk that fixed income securities and other instruments in a Fund's portfolio will decline in value because of an increase in interest rates. As nominal interest rates rise, the value of certain fixed income securities held by a Fund is likely to decrease. A nominal interest rate can be described as the sum of a real interest rate and an expected inflation rate. Interest rate changes can be sudden and unpredictable, and a Fund may lose money as a result of movements in interest rates. A Fund may not be able to hedge against changes in interest rates or may choose not to do so for cost or other reasons. In addition, any hedges may not work as intended.

Fixed income securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than securities with shorter durations. The values of equity and other non-fixed income securities may also decline due to fluctuations in interest rates. Inflation-indexed bonds, including Treasury Inflation-Protected Securities ("TIPS"), decline in value when real interest rates rise. In certain interest rate environments, such as when real interest rates are rising faster than nominal interest rates, inflation-indexed bonds may experience greater losses than other fixed income securities with similar durations.

Variable and floating rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. Conversely, floating rate securities will not generally increase in value if interest rates decline. Inverse floating rate securities may decrease in value if interest rates increase. Inverse floating rate securities may also exhibit greater price volatility than a fixed rate obligation with similar credit quality. When a Fund holds variable or floating rate securities, a decrease (or, in the case of inverse floating rate securities, an increase) in market interest rates will adversely affect the income received from such securities and the NAV of the Fund's shares.

A wide variety of factors can cause interest rates to rise (e.g., central bank monetary policies, inflation rates, general economic conditions, etc.). This is especially true under current economic conditions because interest rates are near historically low levels. Thus, Funds currently face a heightened level of interest rate risk, especially as the Federal Reserve Board ended its quantitative easing program in October 2014 and has begun, and may continue, to raise interest rates. To the extent the Federal Reserve Board continues to raise interest rates, there is a risk that rates across the financial system may rise.

During periods of very low or negative interest rates, a Fund may be unable to maintain positive returns. Interest rates in the U.S. and many parts of the world, including certain European countries, are at or near historically low levels. Certain European countries have recently experienced negative interest rates on certain fixed income instruments. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, may result in heightened market volatility and may detract from Fund performance to the extent a Fund is exposed to such interest rates.

Measures such as average duration may not accurately reflect the true interest rate sensitivity of a Fund. This is especially the case if a Fund consists of securities with widely varying durations. Therefore, if a Fund has an average duration that suggests a certain level of interest rate risk, the Fund may in fact be subject to greater interest rate risk than the average would suggest. This risk is greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund.

Convexity is an additional measure used to understand a security's or Fund's interest rate sensitivity. Convexity measures the rate of change of duration in response to changes in interest rates. With respect to a security's price, a larger convexity (positive or negative) may imply more dramatic price changes in response to changing interest rates. Convexity may be positive or negative. Negative convexity implies that interest rate increases result in increased duration, meaning increased sensitivity in prices in response to rising interest rates. Thus, securities with negative convexity, which may include bonds with traditional call features and certain mortgage-backed securities, may experience greater losses in periods of rising interest rates. Accordingly, if a Fund holds such securities, the Fund may be subject to a greater risk of losses in periods of rising interest rates.

Call risk refers to the possibility that an issuer may exercise its right to redeem a fixed income security earlier than expected (a call). Issuers may call outstanding securities prior to their maturity for a number of reasons (e.g., declining interest rates, changes in credit spreads and improvements in the issuer's credit quality). If an issuer calls a security in which a Fund has invested, the Fund may not recoup the full amount of its initial investment and may be forced to reinvest in lower-yielding securities, securities with greater credit risks or securities with other, less favorable features.

A Fund could lose money if the issuer or guarantor of a fixed income security (including a security purchased with securities lending collateral), or the counterparty to a derivatives contract in the case of each Fund (except the PIMCO Enhanced Short Maturity Active Exchange-Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund), or a repurchase agreement or a loan of portfolio securities, is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The downgrade of the credit of a security held by a Fund may decrease its value. Securities are subject to varying degrees of credit risk, which are often

reflected in credit ratings. Measures such as average credit quality may not accurately reflect the true credit risk of a Fund. This is especially the case if a Fund consists of securities with widely varying credit ratings. Therefore, if a Fund has an average credit rating that suggests a certain credit quality, the Fund may in fact be subject to greater credit risk than the average would suggest. This risk is greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund. Municipal Bonds are subject to the risk that litigation, legislation or other political events, local business or economic conditions, or the bankruptcy of the issuer could have a significant effect on an issuer's ability to make payments of principal and/or interest.

Funds that invest in high yield securities and unrated securities of similar credit quality (commonly known as "high yield securities" or "junk bonds") may be subject to greater levels of credit risk, call risk and liquidity risk than funds that do not invest in such securities. These securities are considered predominantly speculative with respect to an issuer's continuing ability to make principal and interest payments, and may be more volatile than other types of securities. An economic downturn or individual corporate developments could adversely affect the market for these securities and reduce a Fund's ability to sell these securities at an advantageous time or price. An economic downturn would generally lead to a higher non-payment rate and, a high yield security may lose significant market value before a default occurs. High yield securities structured as zero-coupon bonds or pay-in-kind securities tend to be especially volatile as they are particularly sensitive to downward pricing pressures from rising interest rates or widening spreads and may require a Fund to make taxable distributions of imputed income without receiving the actual cash currency. Issuers of high yield securities may have the right to "call" or redeem the issue prior to maturity, which may result in a Fund having to reinvest the proceeds in other high yield securities or similar instruments that may pay lower interest rates. A Fund may also be subject to greater levels of liquidity risk than funds that do not invest in high yield securities. In addition, the high yield securities in which a Fund invests may not be listed on any exchange and a secondary market for such securities may be comparatively illiquid relative to markets for other more liquid fixed income securities. Consequently, transactions in high yield securities may involve greater costs than transactions in more actively traded securities. A lack of publicly-available information, irregular trading activity and wide bid/ask spreads among other factors, may, in certain circumstances, make high yield debt more difficult to sell at an advantageous time or price than other types of securities or instruments. These factors may result in a Fund being unable to realize full value for these securities and/or may result in a Fund not receiving the proceeds from a sale of a high yield security for an extended period after such sale, each of which could result in losses to a Fund. Because of the risks involved in investing in high yield securities, an investment in a Fund that invests in such securities should be considered speculative.

The market price of securities owned by a Fund may go up or down, sometimes rapidly or unpredictably. Securities may decline in value due to factors affecting securities markets generally or particular industries represented in the securities markets. The value of a security may decline due to general market conditions which are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, adverse changes to credit markets or adverse investor sentiment generally. The value of a security may also decline due to factors which affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. During a general downturn in the securities markets, multiple asset classes may decline in value simultaneously. Equity securities generally have greater price volatility than fixed income securities. Credit ratings downgrades may also negatively affect securities held by the Fund. Even when markets perform well, there is no assurance that the investments held by a Fund will increase in value along with the broader market. In addition, market risk includes the risk that geopolitical events will disrupt the economy on a national or global level. For instance, terrorism, market manipulation, government defaults, government shutdowns, political changes or diplomatic developments and natural/environmental disasters can all negatively impact the securities markets, which could cause the Funds to lose value. Any market disruptions could also prevent a Fund from executing advantageous investment decisions in a timely manner. Funds that have focused their investments in a region enduring geopolitical market disruption will face higher risks of loss. Thus, investors should closely monitor current market conditions to determine whether a specific Fund meets their individual financial needs and tolerance for risk.

Current market conditions may pose heightened risks with respect to Funds that invest in fixed income securities. As discussed more under "Interest Rate Risk," interest rates in the U.S. are near historically low levels. However, continued economic recovery, the end of the Federal Reserve Board's quantitative easing program, and an increased likelihood of a continued rising interest rate environment increase the risk that interest rates will continue to rise in the near future. Any further interest rate increases in the future could cause the value of any Fund that invests in fixed income securities to decrease. As such, fixed income securities markets may experience heightened levels of interest rate, volatility and liquidity risk. If rising interest rates cause a Fund to lose enough value, the Fund could also face increased shareholder redemptions, which could force the Fund to liquidate investments at disadvantageous times or prices, therefore adversely affecting the Fund and its shareholders.

Exchanges and securities markets may close early, close late or issue trading halts on specific securities, which may result in, among other things, a Fund being unable to buy or sell certain securities or financial instruments at an advantageous time or accurately price its portfolio investments. In addition, a Fund may rely on various third-party sources to calculate its NAV. As a result, a Fund is subject to certain operational risks associated with reliance on service providers and service providers' data sources. In particular, errors or systems failures and other technological issues may adversely impact the Fund's calculations of its NAV, and such NAV calculation issues may result in inaccurately calculated NAVs, delays in NAV calculation and/or the inability to calculate NAVs over extended periods. A Fund may be unable to recover any losses associated with such failures.

A Fund that invests in Municipal Bonds may be affected significantly by the economic, regulatory or political developments affecting the ability of issuers of Municipal Bonds to pay interest or repay principal. In addition, the ability of an issuer to make payments or repay interest may be affected by litigation or bankruptcy. In the event of bankruptcy of such an issuer, a Fund investing in the issuer's securities could experience delays in collecting principal and interest, and the Fund may not, in all circumstances, be able to collect all principal and interest to which it is entitled. To enforce its rights in the event of a default in the payment of interest or repayment of principal, or both, a Fund may, in some instances, take possession of, and manage, the assets securing the issuer's obligations on such securities, which may increase the Fund's operating expenses. Any income derived from the Fund's ownership or operation of such assets may not be tax-exempt. Municipal Bonds are subject to interest rate, credit and market risk.

Because many Municipal Bonds are issued to finance similar projects (such as those relating to education, health care, housing, transportation, and utilities), conditions in those sectors may affect the overall municipal securities market. In addition, changes in the financial condition of an individual municipal issuer can affect the overall municipal market. Municipal Bonds backed by current or anticipated revenues from a specific project or specific assets can be negatively affected by the discontinuance of the supporting taxation or the inability to collect revenues for the specific project or specific assets. Municipal Bonds are subject to the risk that the Internal Revenue Service (the "IRS") may determine that an issuer has not complied with applicable tax requirements and that interest from the Municipal Bond is taxable, which may result in a significant decline in the value of the security. Municipal Bonds may be less liquid than taxable bonds and there may be less publicly available information on the financial condition of Municipal Bond issuers than for issuers of other securities, and the investment performance of a Fund investing in Municipal Bonds may therefore be more dependent on the analytical abilities of PIMCO than if the Fund held other types of investments such as stocks or taxable bonds. The secondary market for Municipal Bonds also tends to be less well-developed or liquid than many other securities markets, a by-product of lower capital commitments to the asset class by the dealer community, which may adversely affect a Fund's ability to sell Municipal Bonds it holds at attractive prices or value Municipal Bonds.

The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods or services, as well as the historical and prospective earnings of the issuer and the value of its assets. A change in the financial condition of a single issuer may affect securities markets as a whole.

Liquidity risk exists when particular investments are difficult to purchase or sell. Illiquid securities are securities that cannot be disposed of within seven days in the ordinary course of business at approximately the value at which the Fund has valued the securities. Illiquid securities may become harder to value, especially in changing markets. A Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price, which could prevent the Fund from taking advantage of other investment opportunities. Additionally, the market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Bond markets have consistently grown over the past three decades while the capacity for traditional dealer counterparties to engage in fixed income trading has not kept pace and in some cases has decreased. As a result, dealer inventories of corporate bonds, which provide a core indication of the ability of financial intermediaries to "make markets," are at or near historic lows in relation to market size. Because market makers provide stability to a market through their intermediary services, the significant reduction in dealer inventories could potentially lead to decreased liquidity and increased volatility in the fixed income markets. Such issues may be exacerbated during periods of economic uncertainty.

In such cases, a Fund, due to limitations on investments in illiquid securities and the difficulty in purchasing and selling such securities or instruments, may be unable to achieve its desired level of exposure to a certain sector. To the extent that a Fund's principal investment strategies involve securities of companies with smaller market capitalizations, foreign (non-U.S.) securities, Rule 144A securities, illiquid sectors of fixed income securities, derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to liquidity risk. Further, fixed income securities with longer durations until maturity face heightened levels of liquidity risk as compared to fixed income securities with shorter durations until maturity. Finally, liquidity risk also refers to the risk of unusually high redemption requests, redemption requests by certain large shareholders such as institutional investors or asset allocators, or other unusual market conditions that may make it difficult for a Fund to sell investments within the allowable time period to meet redemptions. Meeting such redemption requests could require a Fund to sell securities at reduced prices or under unfavorable conditions, which would reduce the value of the Fund. It may also be the case that other market participants may be attempting to liquidate fixed income holdings at the same time as a Fund, causing increased supply in the market and contributing to liquidity risk and downward pricing pressure. Certain accounts or PIMCO affiliates may from time to time own (beneficially or of record) or control a significant percentage of a Fund's shares. Redemptions by these shareholders of their holdings in a Fund may impact the Fund's liquidity and NAV. These redemptions may also force a Fund to sell securities, which may negatively impact the Fund's brokerage costs.

Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. The various derivative instruments that each Fund (except the PIMCO Enhanced Short Maturity Active Exchange-Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund) may use are referenced under "Characteristics and Risks of Securities and Investment Techniques—Derivatives" in this

prospectus and described in more detail under "Investment Objectives and Policies" in the SAI. The Funds typically use derivatives as a substitute for taking a position in the underlying asset, as part of strategies designed to gain exposure to, for example, issuers, portions of the yield curve, indexes, sectors, currencies, and/or geographic regions, and/or to reduce exposure to other risks, such as interest rate, credit, or currency risk. The Funds may also use derivatives for leverage, in which case their use would involve leveraging risk, and in some cases, may subject a Fund to the potential for unlimited loss. The use of derivatives may cause the Fund's investment returns to be impacted by the performance of securities the Fund does not own and result in the Fund's total investment exposure exceeding the value of its portfolio.

A Fund's use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives are subject to a number of risks described elsewhere in this section, such as liquidity risk (which may be heightened for highly-customized derivatives), interest rate risk, market risk, credit risk and management risk, as well as risks arising from changes in applicable requirements. They also involve the risk of mispricing or improper valuation and the risk that changes in the value of the derivative instrument may not correlate perfectly with the underlying asset, rate or index. By investing in a derivative instrument, the Fund could lose more than the initial amount invested and derivatives may increase the volatility of the Fund, especially in unusual or extreme market conditions. Also, suitable derivative transactions may not be available in all circumstances and there can be no assurance that a Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial or that, if used, such strategies will be successful. In addition, a Fund's use of derivatives may increase or accelerate the amount of taxes payable by shareholders. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with a Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction.

Participation in the markets for derivative instruments involves investment risks and transaction costs to which a Fund may not be subject absent the use of these strategies. The skills needed to successfully execute derivative strategies may be different from those needed for other types of transactions. If the Fund incorrectly forecasts the value and/or creditworthiness of securities, currencies, interest rates, counterparties or other economic factors involved in a derivative transaction, the Fund might have been in a better position if the Fund had not entered into such derivative transaction. In evaluating the risks and contractual obligations associated with particular derivative instruments, it is important to consider that certain derivative transactions may be modified or terminated only by mutual consent of a Fund and its counterparty. Therefore, it may not be possible for the Fund to modify, terminate, or offset the Fund's obligations or the Fund's exposure to the risks associated with a derivative transaction prior to its scheduled termination or maturity date, which may create a possibility of increased volatility and/or decreased liquidity to the Fund. In such case, the Fund may lose money.

Because the markets for certain derivative instruments (including markets located in foreign countries) are relatively new and still developing, appropriate derivative transactions may not be available in all circumstances for risk management or other purposes. Upon the expiration of a particular contract, a Fund may wish to retain a Fund's position in the derivative instrument by entering into a similar contract, but may be unable to do so if the counterparty to the original contract is unwilling to enter into the new contract and no other appropriate counterparty can be found. When such markets are unavailable, a Fund will be subject to increased liquidity and investment risk.

When a derivative is used as a hedge against a position that a Fund holds, any loss generated by the derivative generally should be substantially offset by gains on the hedged investment, and vice versa. Although hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the derivative and the underlying instrument, and there can be no assurance that a Fund's hedging transactions will be effective.

The regulation of the derivatives markets has increased over the past several years, and additional future regulation of the derivatives markets may make derivatives more costly, may limit the availability or reduce the liquidity of derivatives, or may otherwise adversely affect the value or performance of derivatives. Any such adverse future developments could impair the effectiveness or raise the costs of a Fund's derivative transactions, impede the employment of the Fund's derivatives strategies, or adversely affect the Fund's performance.

Equity securities represent an ownership interest, or the right to acquire an ownership interest, in an issuer. Equity securities also include, among other things, preferred securities, convertible stocks and warrants. The values of equity securities, such as common stocks and preferred securities, may decline due to general market conditions which are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. They may also decline due to factors which affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than fixed income securities. These risks are generally magnified in the case of equity investments in distressed companies.

Mortgage-related and other asset-backed securities represent interests in "pools" of mortgages or other assets such as consumer loans or receivables held in trust and often involve risks that are different from or possibly more acute than risks associated with other types of debt instruments. Generally, rising interest rates tend to extend the duration of fixed rate mortgage-related securities, making them more sensitive to changes in interest rates. As a result, in a period of rising interest rates, if a Fund holds mortgage-related securities, it may exhibit additional volatility since individual mortgage holders are less likely to exercise prepayment options, thereby putting additional downward pressure on the value of these securities and potentially causing the Fund to lose money. This is

known as extension risk. Mortgage-backed securities can be highly sensitive to rising interest rates, such that even small movements can cause an investing Fund to lose value. Mortgage-backed securities, and in particular those not backed by a government guarantee, are subject to credit risk. In addition, adjustable and fixed rate mortgage-related securities are subject to prepayment risk. When interest rates decline, borrowers may pay off their mortgages sooner than expected. This can reduce the returns of a Fund because the Fund may have to reinvest that money at the lower prevailing interest rates. A Fund's investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets. Payment of principal and interest on asset-backed securities may be largely dependent upon the cash flows generated by the assets backing the securities, and asset-backed securities may not have the benefit of any security interest in the related assets.

Certain Funds may invest in foreign (non-U.S.) securities and may experience more rapid and extreme changes in value than a Fund that invests exclusively in securities of U.S. companies. The securities markets of many foreign countries are relatively small, with a limited number of companies representing a small number of industries. Additionally, issuers of foreign (non-U.S.) securities are usually not subject to the same degree of regulation as U.S. issuers. Reporting, accounting and auditing standards of foreign countries differ, in some cases significantly, from U.S. standards. Global economies and financial markets are becoming increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market. Also, nationalization, expropriation or confiscatory taxation, currency blockage, political changes or diplomatic developments could adversely affect a Fund's investments in a foreign country. In the event of nationalization, expropriation or other confiscation, a Fund could lose its entire investment in foreign (non-U.S.) securities. Adverse conditions in a certain region can adversely affect securities of other countries whose economies appear to be unrelated. To the extent that a Fund invests a significant portion of its assets in a specific geographic region, the Fund will generally have more exposure to regional economic risks associated with foreign (non-U.S.) investments. Foreign (non-U.S.) securities may also be less liquid and more difficult to value than securities of U.S. issuers.

Foreign (non-U.S.) investment risk may be particularly high to the extent a Fund invests in emerging market securities. Emerging market securities may present market, credit, currency, liquidity, legal, political and other risks different from, and potentially greater than, the risks of investing in securities and instruments economically tied to developed foreign countries. To the extent a Fund invests in emerging market securities that are economically tied to a particular region, country or group of countries, the Fund may be more sensitive to adverse political or social events affecting that region, country or group of countries. Economic, business, political, or social instability may affect emerging market securities differently, and often more severely, than developed market securities. A Fund that focuses its investments in multiple asset classes of emerging market securities may have a limited ability to mitigate losses in an environment that is adverse to emerging market securities in general. Emerging market securities may also be more volatile, less liquid and more difficult to value than securities economically tied to developed foreign countries. The systems and procedures for trading and settlement of securities in emerging markets are less developed and less transparent and transactions may take longer to settle. Rising interest rates, combined with widening credit spreads, could negatively impact the value of emerging market debt and increase funding costs for foreign issuers. In such a scenario, foreign issuers might not be able to service their debt obligations, the market for emerging market debt could suffer from reduced liquidity, and any investing Funds could lose money.

If a Fund invests directly in foreign (non-U.S.) currencies or in securities that trade in, and receive revenues in, foreign (non-U.S.) currencies, or, in the case of each Fund (except the PIMCO Enhanced Short Maturity Active Exchange-Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund), in derivatives that provide exposure to foreign (non-U.S.) currencies, it will be subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency being hedged.

Currency rates in foreign (non-U.S.) countries may fluctuate significantly over short periods of time for a number of reasons, including changes in interest rates, intervention (or the failure to intervene) by U.S. or foreign (non-U.S.) governments, central banks or supranational entities such as the International Monetary Fund, or by the imposition of currency controls or other political developments in the United States or abroad. As a result, a Fund's investments in foreign currency-denominated securities may reduce the returns of the Fund.

Currency risk may be particularly high to the extent that a Fund invests in foreign (non-U.S.) currencies or engages in foreign currency transactions that are economically tied to emerging market countries. These currency transactions may present market, credit, currency, liquidity, legal, political and other risks different from, or greater than, the risks of investing in developed foreign (non-U.S.) currencies or engaging in foreign currency transactions that are economically tied to developed foreign countries.

Certain transactions may give rise to a form of leverage. Such transactions may include, among others, reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions. Each Fund's (except the PIMCO Enhanced Short Maturity Active Exchange-Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund) use of derivatives may also create leveraging risk. In accordance with federal securities laws, rules and staff positions, PIMCO will mitigate its leveraging risk by segregating or "earmarking" liquid assets or otherwise covering

transactions that may give rise to such risk. A Fund also may be exposed to leveraging risk by borrowing money for investment purposes. Leveraging may cause a Fund to liquidate portfolio positions to satisfy its obligations or to meet segregation requirements when it may not be advantageous to do so. Leveraging, including borrowing, may cause a Fund to be more volatile than if the Fund had not been leveraged. This is because leveraging tends to exaggerate the effect of any increase or decrease in the value of a Fund's portfolio securities. Certain types of leveraging transactions, such as short sales that are not "against the box," could theoretically be subject to unlimited losses in cases where a Fund, for any reason, is unable to close out the transaction. In addition, to the extent a Fund borrows money, interest costs on such borrowings may not be recovered by any appreciation of the securities purchased with the borrowed amounts and could exceed the Fund's investment returns, resulting in greater losses. Moreover, to make payments of interest and other loan costs, a Fund may be forced to sell portfolio securities when it is not otherwise advantageous to do so.

Each Fund is subject to management risk because it is an actively managed investment portfolio. PIMCO and each individual portfolio manager will apply investment techniques and risk analysis in making investment decisions for the Funds, but there can be no guarantee that these decisions will produce the desired results. Certain securities or other instruments in which a Fund seeks to invest may not be available in the quantities desired. In addition, regulatory restrictions, actual or potential conflicts of interest or other considerations may cause PIMCO to restrict or prohibit participation in certain investments. In such circumstances, PIMCO or the individual portfolio managers may determine to purchase other securities or instruments as substitutes. Such substitute securities or instruments may not perform as intended, which could result in losses to the Fund. To the extent a Fund employs strategies targeting perceived pricing inefficiencies, arbitrage strategies or similar strategies, it is subject to the risk that the pricing or valuation of the securities and instruments involved in such strategies may change unexpectedly, which may result in reduced returns or losses to the Fund. Additionally, legislative, regulatory, or tax restrictions, policies or developments may affect the investment techniques available to PIMCO and each individual portfolio manager in connection with managing the Funds and may also adversely affect the ability of the Funds to achieve their investment objectives. There also can be no assurance that all of the personnel of PIMCO will continue to be associated with PIMCO for any length of time. The loss of services of one or more key employees of PIMCO could have an adverse impact on the Fund's ability to realize its investment objective.

A Fund that concentrates its investments in California Municipal Bonds may be affected significantly by economic, regulatory or political developments affecting the ability of California issuers to pay interest or repay principal. Certain issuers of California Municipal Bonds have experienced serious financial difficulties in the past and reoccurrence of these difficulties may impair the ability of certain California issuers to pay principal or interest on their obligations. Provisions of the California Constitution and State statutes which limit the taxing and spending authority of California governmental entities may impair the ability of California issuers to pay principal and/or interest on their obligations. While California's economy is broad, it does have major concentrations in high technology, aerospace and defense-related manufacturing, trade, entertainment, real estate and financial services, and may be sensitive to economic problems affecting those industries. Future California political and economic developments, constitutional amendments, legislative measures, executive orders, administrative regulations, litigation and voter initiatives could have an adverse effect on the debt obligations of California issuers.

A Fund that concentrates its investments in New York Municipal Bonds may be affected significantly by economic, regulatory or political developments affecting the ability of New York issuers to pay interest or repay principal. While New York's economy is broad, it does have concentrations in the financial services industry, and may be sensitive to economic problems affecting that industry. Certain issuers of New York Municipal Bonds have experienced serious financial difficulties in the past and reoccurrence of these difficulties may impair the ability of certain New York issuers to pay principal or interest on their obligations. The financial health of New York City affects that of the State, and when New York City experiences financial difficulty it may have an adverse affect on New York Municipal Bonds held by such Fund. The growth rate of New York has at times been somewhat slower than the nation overall. The economic and financial condition of New York also may be affected by various financial, social, economic and political factors.

A Fund may be more sensitive to adverse economic, business or political developments if it invests a substantial portion of its assets in the bonds of specific projects (such as those relating to education, health care, housing, transportation, and utilities), industrial development bonds, or in general obligation bonds, particularly if there is a large concentration from issuers in a single state. This is because the value of municipal securities can be significantly affected by the political, economic, legal, and legislative realities of the particular issuer's locality or municipal sector events. In addition, a significant restructuring of federal income tax rates or even serious discussion on the topic in Congress could cause municipal bond prices to fall. The demand for municipal securities is strongly influenced by the value of tax-exempt income to investors. Lower income tax rates could reduce the advantage of owning municipal securities. Similarly, changes to state or federal regulation tied to a specific sector, such as the hospital sector, could have an impact on the revenue stream for a given subset of the market.

Municipal securities are also subject to interest rate, credit, and liquidity risk.

Interest Rate Risk. The value of municipal securities, similar to other fixed income securities, will likely drop as interest rates rise in the general market. Conversely, when rates decline, bond prices generally rise.

Credit Risk. The risk that a borrower may be unable to make interest or principal payments when they are due. Funds that invest in municipal securities rely on the ability of the issuer to service its debt. This subjects a Fund to credit risk in that the municipal issuer may be fiscally unstable or exposed to large liabilities that could impair its ability to honor its

obligations. Municipal issuers with significant debt service requirements, in the near-to mid-term; unrated issuers and those with less capital and liquidity to absorb additional expenses may be most at risk. A Fund that invests in lower quality or high yield municipal securities may be more sensitive to the adverse credit events in the municipal market. The treatment of municipalities in bankruptcy is more uncertain, and potentially more adverse to debt holders, than for corporate issues.

Liquidity Risk. The risk that investors may have difficulty finding a buyer when they seek to sell, and therefore, may be forced to sell at a discount to the market value. Liquidity may sometimes be impaired in the municipal market and Funds that primarily invest in municipal securities may find it difficult to purchase or sell such securities at opportune times. Liquidity can be impaired due to interest rate concerns, credit events, or general supply and demand imbalances. These adverse developments sometimes cause a Fund to endure higher redemption rates. Depending on the particular issuer and current economic conditions, municipal securities could be deemed more volatile investments.

In addition to general municipal market risks, different municipal sectors may face different risks. For instance, general obligation bonds are secured by the full faith, credit, and taxing power of the municipality issuing the obligation. As such, timely payment depends on the municipality's ability to raise tax revenue and maintain a fiscally sound budget. The timely payments may also be influenced by any unfunded pension liabilities or other post-employee benefit plan ("OPEB") liabilities.

Revenue bonds are secured by special tax revenues or other revenue sources. If the specified revenues do not materialize, then the bonds may not be repaid.

Private activity bonds are yet another type of municipal security. Municipalities use private activity bonds to finance the development of industrial facilities for use by private enterprise. Principal and interest payments are to be made by the private enterprise benefitting from the development, which means that the holder of the bond is exposed to the risk that the private issuer may default on the bond.

Moral obligation bonds are usually issued by special purpose public entities. If the public entity defaults, repayment becomes a "moral obligation" instead of a legal one. The lack of a legally enforceable right to payment in the event of default poses a special risk for a holder of the bond because it has little or no ability to seek recourse in the event of default.

Municipal notes are similar to general municipal debt obligations, but they generally possess shorter terms. Municipal notes can be used to provide interim financing and may not be repaid if anticipated revenues are not realized.

A Fund's short sales, if any, are subject to special risks. A short sale involves the sale by the Fund of a security that it does not own with the hope of purchasing the same security at a later date at a lower price. A Fund may also enter into a short position through a forward commitment or, in the case of each Fund (except the PIMCO Enhanced Short Maturity Active Exchange-Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund), a short derivative position through a futures contract or swap agreement. If the price of the security or derivative has increased during this time, then the Fund will incur a loss equal to the increase in price from the time that the short sale was entered into plus any transaction costs (i.e., premiums and interest) paid to the broker-dealer to borrow securities.

Therefore, short sales involve the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment. By contrast, a loss on a long position arises from decreases in the value of the security and is limited by the fact that a security's value cannot decrease below zero.

By investing the proceeds received from selling securities short, a Fund could be deemed to be employing a form of leverage, which creates special risks. The use of leverage may increase a Fund's exposure to long security positions and make any change in the Fund's NAV greater than it would be without the use of leverage. This could result in increased volatility of returns. There is no guarantee that any leveraging strategy a Fund employs will be successful during any period in which it is employed.

In times of unusual or adverse market, economic, regulatory or political conditions, a Fund may not be able, fully or partially, to implement its short selling strategy. Periods of unusual or adverse market, economic, regulatory or political conditions generally may exist for as long as six months and, in some cases, much longer. Also, there is the risk that the third party to the short sale will not fulfill its contractual obligations, causing a loss to the Fund.

Convertible securities are fixed income securities, preferred securities or other securities that are convertible into or exercisable for common stock of the issuer (or cash or securities of equivalent value) at either a stated price or a stated rate. The market values of convertible securities may decline as interest rates increase and, conversely, may increase as interest rates decline. A convertible security's market value, however, tends to reflect the market price of the common stock of the issuing company when that stock price approaches or is greater than the convertible security's "conversion price." The conversion price is defined as the predetermined price at which the convertible security could be exchanged for the associated stock. As the market price of the underlying common stock declines, the price of the convertible security tends to be influenced more by the yield of the convertible security. Thus, it may not decline in price to the same extent as the underlying common stock. In the event of a liquidation of the issuing company, holders of convertible securities may be paid before the company's common stockholders but after holders of any senior debt obligations of the company. Consequently, the issuer's convertible securities generally entail less risk than its common stock but more risk than its debt obligations.

Synthetic convertible securities involve the combination of separate securities that possess the two principal characteristics of a traditional convertible security (i.e., an income-producing component and a right to acquire an equity security). Synthetic convertible securities are often achieved, in part, through investments in warrants or options to buy common stock (or options on a stock index), and therefore are subject to

the risks associated with derivatives. The value of a synthetic convertible security will respond differently to market fluctuations than a traditional convertible security because a synthetic convertible is composed of two or more separate securities or instruments, each with its own market value. Because the convertible component is typically achieved by investing in warrants or options to buy common stock at a certain exercise price, or options on a stock index, synthetic convertible securities are subject to the risks associated with derivatives. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

A Fund may engage in investment strategies intended to manage capital gain distributions. For example, a Fund may attempt to use losses from sales of securities that have declined to offset future gains that would otherwise be taxable. Any such strategy may be unsuccessful or only partially successful, and investors may experience adverse tax effects, including, but not limited to potentially greater tax liability than other PIMCO-advised funds. Additionally, such strategies may reduce investment returns or result in investment losses, which could cause the Fund and investors to lose money. Further, a Fund's focus on income generation may result in a higher overall tax liability as income may be taxed at a higher rate than capital gains.

Although a Fund may seek to maintain a stable distribution rate, the Fund's distribution rate may be affected by numerous factors, including but not limited to changes in realized and projected market returns, fluctuations in market interest rates, Fund performance, and other factors. For instance, during periods of low or declining interest rates, the Fund's distributable income and dividend levels may decline for many reasons. There can be no assurance that a change in market conditions or other factors will not result in a change in the Fund's distribution rate or that the rate will be sustainable in the future.

Please see "Disclosure of Portfolio Holdings" in the SAI for information about the availability of the complete schedule of each Fund's holdings.

PIMCO serves as the investment manager for the Funds. Subject to the supervision of the Board of Trustees, PIMCO is responsible for managing the investment activities of the Funds and the Funds' business affairs and other administrative matters.

PIMCO is located at 650 Newport Center Drive, Newport Beach, CA 92660. Organized in 1971, PIMCO provides investment management and advisory services to private accounts of institutional and individual clients and to mutual funds. As of September 30, 2018, PIMCO had approximately $1.72 trillion in assets under management.

Each Fund pays for the advisory, supervisory and administrative services it requires under what is essentially an all-in fee structure. For the fiscal year ended June 30, 2018, the Funds paid monthly Management Fees to PIMCO at the following annual rates (stated as a percentage of the average daily net assets of the Fund taken separately):

1 For details regarding changes to this rate within the last 5 years, please see the footnote disclosures for the Funds in the Financial Highlights section beginning on page 52.

The PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund were not operational during the fiscal year ended June 30, 2018. The management fees for each of the PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund are at the annual rate (stated as a percentage of the average daily net assets of each Fund taken separately) of 0.25%.

In addition to providing investment advisory services, PIMCO provides or procures supervisory and administrative services for shareholders and also bears the costs of various third-party services required by the Funds, including audit, custodial, portfolio accounting, legal, transfer agency and printing costs. The Funds bear other expenses which are not covered under the management fee which may vary and affect the total level of expenses paid by shareholders, such as taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, securities lending expenses, extraordinary expenses (such as litigation and indemnification expenses) and fees and expenses of the Trust's Independent Trustees and their counsel. PIMCO generally earns a profit on the management fee paid by the Funds. Also, under the terms of the investment management agreement, PIMCO, and not Fund shareholders, would benefit from any price decreases in third-party services, including decreases resulting from an increase in net assets.

A discussion of the basis for the Board of Trustees' approval of the Funds' (other than the PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund) investment management agreement is available in the Funds' semi-annual report to shareholders for the fiscal half-year ended December 31, 2017. A discussion of the basis for the Board of Trustees' approval of the PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund's investment management agreement will be available in the Fund's first annual or semi-annual report to shareholders.

Pursuant to the Expense Limitation Agreement, PIMCO has agreed to waive a portion of each Fund's Management Fee, or reimburse the Fund, to the extent that the Fund's organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata share of Trustee fees exceed 0.0049% (the "Expense Limit") (calculated as a percentage of average daily net assets). The Expense Limitation Agreement will automatically renew for one-year terms unless PIMCO provides written notice to the Trust at least 30 days prior to the end of the then current term. In any month in which the investment management agreement is in effect, PIMCO is entitled to reimbursement by each Fund of any portion of the Management Fee waived or reimbursed as set forth above (the "Reimbursement Amount") during the previous thirty-six months, provided that such amount paid to PIMCO will not: 1) together with any organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata Trustee fees, exceed, for such month, the Expense Limit; 2) exceed the total Reimbursement Amount; or 3) include any amounts previously reimbursed to PIMCO.

PIMCO has contractually agreed, through October 31, 2019, to waive or reduce its Management Fee in an amount equivalent to the PIMCO Active Bond Exchange-Traded Fund's expenses or costs attributable to the Securities and Exchange Commission's ("SEC") investigation and related settlement proceedings identified in Investment Advisers Act of 1940 Release No. 4577, dated December 1, 2016. This arrangement renews annually for a full year unless terminated by PIMCO upon at least 30 days' notice prior to the end of the contract term. PIMCO may not recoup these waivers or reductions. The

contractual agreement described in the preceding three sentences (the "BOND Agreement") amends and restates a prior contractual agreement (the "Prior Agreement") under which PIMCO agreed to waive or reduce its Management Fee payable by the Fund subject to certain conditions. While recoupment was permitted under the Prior Agreement, the BOND Agreement requires PIMCO to reimburse the Fund for any amounts previously recouped by PIMCO pursuant to the Prior Agreement.

PIMCO has contractually agreed, through October 31, 2019, to waive its management fee by 0.07% of the average daily net assets of the PIMCO Enhanced Low Duration Active Exchange-Traded Fund. This waiver will automatically renew for one-year terms unless PIMCO provides written notice to the Trust at least 30 days prior to the end of the then current term. In any month in which the investment management agreement is in effect, PIMCO is entitled to reimbursement by the Fund of any portion of the management fee waived as set forth above (the "Fee Waiver Reimbursement Amount") during the previous thirty-six months, provided that such amount paid to PIMCO will not: 1) together with any recoupment of organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata Trustee fees pursuant to the Expense Limitation Agreement, exceed the Expense Limit; 2) exceed the total Fee Waiver Reimbursement Amount; or 3) include any amounts previously reimbursed to PIMCO.

To maintain certain net yields for the PIMCO Government Limited Maturity Active Exchange-Traded and PIMCO Prime Limited Maturity Active Exchange-Traded Funds, PIMCO and certain affiliates have entered into a fee and expense limitation agreement with such Funds (the "Agreement") pursuant to which PIMCO or its affiliates may, to the extent permitted by applicable law, temporarily and voluntarily waive, reduce or reimburse all or any portion of: (i) first, any distribution and/or service (12b-1) fees applicable to the Fund; and (ii) second, to the extent necessary, the Fund's management fee, each waiver, reduction or reimbursement in an amount and for a period of time as determined by PIMCO or its affiliates.

In any month in which the investment management agreement is in effect, PIMCO may recoup from the Fund any portion of the management fee waived, reduced or reimbursed pursuant to the Agreement (the "Reimbursement Amount") during the previous 36 months, provided that such amount paid to PIMCO will not: 1) together with any recoupment of organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata Trustee fees pursuant to the expense limitation agreement between PIMCO and the Trust, exceed the Expense Limit; 2) exceed the total Reimbursement Amount; 3) include any amounts previously reimbursed to PIMCO; or 4) cause any Fund to maintain a net negative yield. The Reimbursement Amount will be reimbursed in the same order that fees were waived as described above, except the Funds will not reimburse PIMCO or its affiliates for any portion of the distribution and/or service (12b-1) fees waived, reduced or reimbursed pursuant to the Agreement. There is no guarantee that the Funds will maintain a positive net yield.

The Trust does not currently authorize payment of any distribution and/or service (12b-1) fees. If distribution and/or service (12b-1) fees are authorized in the future, to the extent PIMCO or its affiliates waive, reduce or reimburse any portion of the distribution and/or service (12b-1) fees pursuant to the Agreement, PIMCO or its affiliates may pay or reimburse financial institutions for services for which such financial institutions normally receive distribution and/or service (12b-1) fees from the applicable Fund out of PIMCO's or its affiliates' own assets. These payments and reimbursements may be made from profits received by PIMCO from management fees paid to PIMCO by the Funds. Such activities by PIMCO or its affiliates may provide incentives to financial institutions to purchase or market shares of the Funds. Additionally, these activities may give PIMCO or its affiliates additional access to sales representatives of such financial institutions, which may increase sales Fund shares.

The following individuals have primary responsibility for managing each of the noted Funds.

Please see the SAI for additional information about other accounts managed by the portfolio managers, the portfolio managers' compensation and the portfolio managers' ownership of shares of the Funds.

The Trustees are responsible generally for overseeing the management of the Trust. The Trustees authorize the Trust to enter into service agreements with the Investment Adviser, the Distributor (as defined below) and other service providers in order to provide, and in some cases authorize service providers to procure through other parties, necessary or desirable services on behalf of the Trust and the Funds. Shareholders are not parties to or third-party beneficiaries of such service agreements. Neither this prospectus nor summary prospectus, the Trust's SAI, any contracts filed as exhibits to the Trust's registration statement, nor any other communications, disclosure documents or regulatory filings from or on behalf of the Trust or a Fund creates a contract between or among any shareholder of a Fund, on the one hand, and the Trust, a Fund, a service provider to the Trust or a Fund, and/or the Trustees or officers of the Trust, on the other hand. The Trustees (or the Trust and its officers, service providers or other delegates acting under authority of the Trustees) may amend this, or use a new prospectus, summary prospectus or SAI with respect to a Fund or the Trust, and/or amend, file and/or issue any other communications, disclosure documents or regulatory filings, and may amend or enter into any contracts to which the Trust or a Fund is a party, and interpret the investment objective(s), policies, restrictions and contractual provisions applicable to any Fund, without shareholder input or approval, except in circumstances in which shareholder approval is specifically required by law (such as changes to fundamental investment policies) or where a shareholder approval requirement is specifically disclosed in the Trust's then-current prospectus or SAI.

The Trust's Distributor is PIMCO Investments LLC (the "Distributor"). The Distributor, located at 1633 Broadway, New York, NY 10019, is a broker-dealer registered with the SEC. The Distributor distributes Creation Units for the Funds and does not maintain a secondary market in shares of the Funds.

The Trust has adopted a Distribution and Servicing Plan (the "12b-1 Plan") for shares of the Funds pursuant to Rule 12b-1 under the Investment Company Act of 1940, as amended (the "1940 Act"). The 12b-1 Plan permits compensation in connection with the distribution and marketing of Fund shares and/or the provision of certain shareholder services. The 12b-1 Plan permits the Fund to pay compensation at an annual rate of up to 0.25% of the Fund's average daily net assets. However, the Board of Trustees has determined not to authorize payment of a 12b-1 Plan fee at this time.

The 12b-1 fee may only be imposed or increased when the Board of Trustees determines that it is in the best interests of shareholders to do so. Because these fees are paid out of the Fund's assets on an ongoing basis, to the extent that a fee is authorized, over time they will increase the cost of an investment in the Fund. The 12b-1 Plan fee may cost an investor more than other types of sales charges.

PIMCO and/or the Distributor ("PIMCO Entities") may make payments to broker-dealers or other financial intermediaries (each, an "Intermediary") related to activities that are designed to make registered representatives, other professionals and individual investors more knowledgeable about the Funds or for other activities, such as participation in marketing activities and presentations, educational training programs, the support of technology platforms and/or reporting systems. PIMCO Entities may also make payments to Intermediaries for certain printing, publishing and mailing costs associated with the Funds or materials relating to ETFs in general. In addition, PIMCO Entities may make payments to Intermediaries that make Fund shares available to their clients or for otherwise promoting the Funds. Such payments, which may be significant to the Intermediary, are not made by a Fund. Rather, such payments are made by PIMCO Entities from their own resources, which may come directly or indirectly in part from management fees paid by the Funds. Payments of this type are sometimes referred to as marketing support or revenue-sharing payments. An Intermediary may make decisions about which investment options it recommends or makes available, or the level of services provided, to its customers based on the marketing support payments it is eligible to receive. Therefore, such payments to an Intermediary create conflicts of interest between the Intermediary and its customers and may cause the Intermediary to

recommend a Fund over another investment. More information regarding these payments is contained in the SAI. A shareholder should contact his or her Intermediary's salesperson or other investment professional for more information regarding any such payments the Intermediary firm may receive from PIMCO Entities.

Shares of the Funds are listed for trading on a national securities exchange during the trading day. Shares can be bought and sold throughout the trading day like shares of other publicly traded companies. However, there can be no guarantee that an active trading market will develop or be maintained, or that the Fund shares listing will continue or remain unchanged. The Trust does not impose any minimum investment for shares of a Fund purchased on an exchange. Buying or selling a Fund's shares involves certain costs that apply to all securities transactions. When buying or selling shares of a Fund through a financial intermediary, you may incur a brokerage commission or other charges determined by your financial intermediary. Due to these brokerage costs, if any, frequent trading may detract significantly from investment returns. In addition, you may also incur the cost of the spread (the difference between the bid price and the ask price). The commission is frequently a fixed amount and may be a significant cost for investors seeking to buy or sell small amounts of shares. The spread varies over time for shares of a Fund based on its trading volume and market liquidity, and is generally less if the Fund has more trading volume and market liquidity and more if the Fund has less trading volume and market liquidity.

Shares of a Fund may be acquired through the Distributor or redeemed directly with the Fund only in Creation Units or multiples thereof, as discussed in the "Creations and Redemptions" section of the SAI. Once created, shares of a Fund generally trade in the secondary market in amounts less than a Creation Unit.

The Trust's Board of Trustees has not adopted a policy of monitoring for frequent purchases and redemptions of Fund shares ("frequent trading") that appear to attempt to take advantage of potential arbitrage opportunities presented by a lag between a change in the value of a Fund's portfolio securities after the close of the primary markets for the Fund's portfolio securities and the reflection of that change in the Fund's NAV ("market timing"). The Trust believes this is appropriate because an ETF, such as each Fund, is intended to be attractive to arbitrageurs, as trading activity is critical to ensuring that the market price of Fund shares remains at or close to NAV. Since each Fund issues and redeems Creation Units at NAV plus applicable transaction fees, and each Fund's shares may be purchased and sold on NYSE Arca at prevailing market prices, the risks of frequent trading are limited.

Each Fund's primary listing exchange is NYSE Arca. NYSE Arca is open for trading Monday through Friday and is closed on the following holidays: New Year's Day, Martin Luther King, Jr. Day, Presidents' Day, Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day.

A "Business Day" with respect to the Funds is each day NYSE Arca is open. Orders from Authorized Participants to create or redeem Creation Units will only be accepted on a Business Day. On days when NYSE Arca closes earlier than normal, a Fund may require orders to create or redeem Creation Units to be placed earlier in the day. See the SAI.

Section 12(d)(1) of the 1940 Act restricts investments by registered investment companies and companies relying on Sections 3(c)(1) or 3(c)(7) of the 1940 Act in the securities of other investment companies. Registered investment companies are permitted to invest in the Funds beyond the limits set forth in Section 12(d)(1), subject to certain terms and conditions set forth in an SEC exemptive order issued to PIMCO and the Trust, including that such investment companies enter into an agreement with the Trust.

The Trust typically does not offer or sell its shares to non-U.S. resident Authorized Participants. For purposes of this policy, a U.S. resident is defined as an account with (i) a U.S. address of record and (ii) all account owners residing in the U.S. at the time of sale.

Shares of a Fund are held in book-entry form, which means that no stock certificates are issued. The Depository Trust Company ("DTC") or its nominee is the record owner of all outstanding shares of the Funds and is recognized as the owner of all shares for all purposes.

Investors owning shares of a Fund are beneficial owners as shown on the records of DTC or its participants. DTC serves as the securities depository for shares of the Funds. DTC participants include securities brokers and dealers, banks, trust companies, clearing corporations and other institutions that directly or indirectly maintain a custodial relationship with DTC. As a beneficial owner of shares, you are not entitled to receive physical delivery of stock certificates or to have shares registered in your name, and you are not considered a registered owner of shares. Therefore, to exercise any right as an owner of shares, you must rely upon the procedures of DTC and its participants. These procedures are the same as those that apply to any other exchange-traded securities that you hold in book-entry or "street name" form.

The trading prices of a Fund's shares in the secondary market generally differ from the Fund's daily NAV per share and are affected by market forces such as supply and demand, economic conditions and other factors. Information regarding the intraday indicative value ("IIV") of a Fund is disseminated every 15 seconds throughout the trading day by the national securities exchange on which the Fund's shares are primarily listed or by market data vendors or other information providers. The IIV is based on the current market value of the securities and/or cash included in a Fund's IIV basket. The IIV does not necessarily reflect the precise composition of the current portfolio of securities and instruments held by a Fund at a particular point in time or the best possible valuation of the current portfolio. Unlike a Fund's NAV, the IIV may not reflect estimated accrued interest, dividends and other income, or Fund expenses. Therefore, the IIV should not be viewed as a "real-time" update of the NAV, which is computed only once a day. The IIV is generally determined by using both current market quotations and/or price quotations obtained from broker-dealers that may trade in the portfolio securities and instruments included in a Fund's IIV basket. The Fund is not involved in, or responsible for, the calculation or dissemination of the IIV and makes no representation or warranty as to its accuracy. An inaccuracy in the IIV could result from various factors, including the difficulty of pricing portfolio instruments on an intraday basis.

There may be differences between the daily market prices on secondary markets for shares of a Fund and the Fund's NAV. NAV is the price per share at which the Fund issues and redeems shares. See "How Net Asset Value Is Determined" below. The price used to calculate market returns ("Market Price") of a Fund generally is determined using the midpoint between the highest bid and the lowest offer on the national securities exchange on which shares of the Fund are primarily listed for trading, as of the time that the Fund's NAV is calculated. A Fund's Market Price may be at, above or below its NAV. The NAV of a Fund will fluctuate with changes in the market value of its portfolio holdings. The Market Price of a Fund will fluctuate in accordance with changes in its NAV, as well as market supply and demand.

Premiums or discounts are the differences (expressed as a percentage) between the NAV and the Market Price of a Fund on a given day, generally at the time the NAV is calculated. A premium is the amount that a Fund is trading above the reported NAV, expressed as a percentage of the NAV. A discount is the amount that a Fund is trading below the reported NAV, expressed as a percentage of the NAV. A discount or premium could be significant. Information regarding the frequency of daily premiums or discounts, generally at the time the NAV is calculated, during a Fund's four previous calendar quarters (or for the life of the Fund, if shorter) can be found at www.pimcoetfs.com.

To reduce expenses, it is intended that only one copy of the Funds' prospectus and each annual and semi-annual report, when available, will be mailed to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please contact the financial intermediary through which you hold your shares.

The NAV of a Fund is determined by dividing the total value of a Fund's portfolio investments and other assets attributable to that Fund, less any liabilities, by the total number of shares outstanding of that Fund.

On each day that the NYSE is open, Fund shares are ordinarily valued as of the close of regular trading ("NYSE Close"). Information that becomes known to the Funds or their agents after the time as of which NAV has been calculated on a particular day will not generally be used to retroactively adjust the price of a security or the NAV determined earlier that day. Each Fund reserves the right to change the time its respective NAV is calculated if the Fund closes earlier, or as permitted by the SEC.

For purposes of calculating NAV, portfolio securities and other assets for which market quotes are readily available are valued at market value. Market value is generally determined on the basis of official closing prices or the last reported sales prices, or if no sales are reported, based on quotes obtained from established market makers or prices (including evaluated prices) supplied by the Funds' approved pricing services, quotation reporting systems and other third-party sources (together, "Pricing Services"). The Funds will normally use pricing data for domestic equity securities received shortly after the NYSE Close and do not normally take into account trading, clearances or settlements that take place after the NYSE Close. A foreign (non-U.S.) equity security traded on a foreign exchange or on more than one exchange is typically valued using pricing information from the exchange considered by PIMCO to be the primary exchange. If market value pricing is used, a foreign (non-U.S.) equity security will be valued as of the close of trading on the foreign exchange, or the NYSE Close, if the NYSE Close occurs before the end of trading on the foreign exchange. Domestic and foreign (non-U.S.) fixed income securities, non-exchange-traded derivatives, and equity options are normally valued on the basis of quotes obtained from brokers and dealers or Pricing Services using data reflecting the earlier closing of the principal markets for those securities. Prices obtained from Pricing Services may be based on, among other things, information provided by market makers or estimates of market values obtained from yield data relating to investments or securities with similar characteristics. Certain fixed income securities purchased on a delayed-delivery basis are marked to market daily until settlement at the forward settlement date. Exchange-traded options, except equity options, futures and options on futures are valued at the settlement price determined by the relevant exchange. Swap agreements are valued on the basis of bid quotes obtained from brokers and dealers or market-based prices supplied by Pricing Services or other pricing sources. With respect to any portion of a Fund's assets that are invested in one or more open-end management investment companies (other than ETFs), the Fund's NAV will be calculated based upon the NAVs of such investments.

If a foreign (non-U.S.) equity security's value has materially changed after the close of the security's primary exchange or principal market but before the NYSE Close, the security may be valued at fair value based on procedures established and approved by the Board of Trustees. Foreign (non-U.S.) equity securities that do not trade when the NYSE is open are also valued at fair value. With respect to foreign (non-U.S.) equity securities, the Fund may determine the fair value of investments based on information provided by Pricing Services and other third-party vendors, which may recommend fair value or adjustments with reference to other securities, indexes or assets. In considering whether fair valuation is required and in determining fair values, the Fund may, among other things, consider significant events (which may be considered to include changes in the value of U.S. securities or securities indexes) that occur after the close of the relevant market and before the NYSE Close. A Fund may utilize modeling tools provided by third-party vendors to determine fair values of non-U.S. securities. For these purposes, any movement in the applicable reference index or instrument ("zero trigger") between the earlier close of the applicable foreign market and the NYSE Close may be deemed to be a significant event, prompting the application of the pricing model (effectively resulting in daily fair valuations). Foreign (non-U.S.) exchanges may permit trading in foreign (non-U.S.) equity securities on days when the Trust is not open for business, which may result in a Fund's portfolio investments being affected when you are unable to buy or sell shares.

rate loan at fair value, the factors considered may include, but are not limited to, the following: (a) the creditworthiness of the borrower and any intermediate participants, (b) the terms of the loan, (c) recent prices in the market for similar loans, if any, and (d) recent prices in the market for instruments of similar quality, rate, period until next interest rate reset and maturity.

Investments for which market quotes or market based valuations are not readily available are valued at fair value as determined in good faith by the Board of Trustees or persons acting at their direction. The Board of Trustees has adopted methods for valuing securities and other assets in circumstances where market quotes are not readily available, and has delegated to PIMCO the responsibility for applying the fair valuation methods. In the event that market quotes or market based valuations are not readily available, and the security or asset cannot be valued pursuant to a Board approved valuation method, the value of the security or asset will be determined in good faith by the Valuation Oversight Committee of the Board of Trustees, generally based on recommendations provided by PIMCO. Market quotes are considered not readily available in circumstances where there is an absence of current or reliable market-based data (e.g., trade information, bid/ask information, broker quotes, Pricing Services' prices), including where events occur after the close of the relevant market, but prior to the NYSE Close, that materially affect the values of the Fund's securities or assets. In addition, market quotes are considered not readily available when, due to extraordinary circumstances, the exchanges or markets on which the securities trade do not open for trading for the entire day and no other market prices are available. The Board of Trustees has delegated to PIMCO the responsibility for monitoring significant events that may materially affect the values of the Fund's securities or assets and for determining whether the value of the applicable securities or assets should be reevaluated in light of such significant events.

When the Fund uses fair valuation to determine the value of a portfolio security or other asset for purposes of calculating its NAV, such investments will not be priced on the basis of quotes from the primary market in which they are traded, but rather may be priced by another method that the Board of Trustees or persons acting at their direction believe reflects fair value. Fair valuation may require subjective determinations about the value of a security. While the Trust's policy is intended to result in a calculation of the Fund's NAV that fairly reflects security values as of the time of pricing, the Trust cannot ensure that fair values determined by the Board of Trustees or persons acting at their direction would accurately reflect the price that a Fund could obtain for a security if it were to dispose of that security as of the time of pricing (for instance, in a forced or distressed sale). The prices used by the Fund may differ from the value that would be realized if the securities were sold.

Each Fund distributes substantially all of its net investment income to shareholders in the form of dividends. The Funds intend to declare and distribute income dividends monthly to shareholders of record. In addition, each Fund distributes any net capital gains earned from the sale of portfolio securities to shareholders no less frequently than annually. Net short-term capital gains may be paid more frequently. Dividend payments are made through DTC participants and indirect participants to beneficial owners then of record with proceeds received from the Funds.

No dividend reinvestment service is provided by the Trust. Financial intermediaries may make available the DTC book-entry Dividend Reinvestment Service for use by beneficial owners of Fund shares for reinvestment of their dividend distributions. Beneficial owners should contact their financial intermediary to determine the availability and costs of the service and the details of participation therein. Financial intermediaries may require beneficial owners to adhere to specific procedures and timetables. If this service is available and used, dividend distributions of both income and net capital gains will be automatically reinvested in additional whole shares of the Fund purchased in the secondary market.

The following information is meant as a general summary for U.S. taxpayers. Please see the SAI for additional information. You should rely on your own tax adviser for advice about the particular federal, state and local tax consequences to you of investing in any Fund.

Taxes on Fund Distributions. If you are subject to U.S. federal income tax, you will be subject to tax on taxable Fund distributions, other than exempt-interest dividends paid by the PIMCO Short Term Municipal Bond Active Exchange-Traded Fund and PIMCO Intermediate Municipal Bond Active Exchange-Traded Fund, as discussed below. For federal income tax purposes, taxable Fund distributions will be taxable to you as either ordinary income or capital gains.

Fund taxable dividends (i.e., distributions of investment income) are generally taxable to you as ordinary income. Federal taxes on Fund distributions of gains are determined by how long a Fund owned the investments that generated the gains, rather than how long you have owned your shares. Distributions of gains from investments that the Fund owned for more than one year will generally be taxable to you as long-term capital gains. Distributions of gains from investments that the Fund owned for one year or less.

The tax treatment of income, gains and losses attributable to foreign currencies (and derivatives on such currencies), and various other special tax rules applicable to certain financial transactions and instruments could affect the amount, timing and character of a Fund's distributions. In some cases, these tax rules could also result in a retroactive change in the tax character of prior distributions and may also possibly cause all, or a portion,

of prior distributions to be reclassified as returns of capital for tax purposes. See "Returns of Capital" below.

Taxable Fund distributions are taxable to you even if they are paid from income or gains earned by a Fund prior to your investment and thus were included in the price you paid for your shares. For example, if you purchase shares on or just before the record date of a Fund distribution, you will pay full price for the shares and may receive a portion of your investment back as a taxable distribution.

Taxes When You Sell Your Shares. Any gain resulting from the sale of Fund shares will generally be subject to federal income tax. Currently, any capital gain or loss realized upon a sale of Fund shares is generally treated as a long-term gain or loss if the shares have been held for more than one year. Any capital gain or loss realized upon a sale of Fund shares held for one year or less is generally treated as short-term gain or loss, except that any capital loss on the sale of shares held for six months or less is treated as long-term capital loss to the extent that capital gain dividends were paid with respect to such shares.

Returns of Capital. If a Fund's distributions exceed its taxable income and capital gains realized during a taxable year, all or a portion of the distributions made in the same taxable year may be recharacterized as a return of capital to shareholders. A return of capital distribution will generally not be taxable, but will reduce each shareholder's cost basis in the Fund and result in a higher reported capital gain or lower reported capital loss when those shares on which the distribution was received are sold.

Medicare Tax. An additional 3.8% Medicare tax is imposed on certain net investment income (including ordinary dividends and capital gain distributions received from a Fund and net gains from redemptions or other taxable dispositions of Fund shares) of U.S. individuals, estates and trusts to the extent that such person's "modified adjusted gross income" (in the case of an individual) or "adjusted gross income" (in the case of an estate or trust) exceeds certain threshold amounts.

Important Tax Reporting Considerations. The Internal Revenue Code of 1986 requires reporting of adjusted cost basis information for covered securities, which generally include shares of a regulated investment company acquired after January 1, 2012, to the IRS. Shareholders should contact their financial intermediaries with respect to reporting of cost basis and available elections for their accounts.

Backup Withholding. Shareholders may be required to withhold U.S. federal income tax on all taxable distributions payable to shareholders if they fail to provide the Fund with their correct taxpayer identification number or to make required certifications, or if they have been notified by the IRS that they are subject to backup withholding. Backup withholding is not an additional tax. Any amounts withheld may be credited against U.S. federal income tax liability.

Foreign Withholding Taxes. A Fund may be subject to foreign withholding or other foreign taxes, which in some cases can be significant on any income or gain from investments in foreign securities. In that case, the Fund's total return on those securities would be decreased. Each Fund may generally deduct these taxes in computing its taxable income. Rather than deducting these foreign taxes, if more than 50% of the value of a Fund's total assets at the close of its taxable year consists of stock or securities of foreign corporations or foreign governments, or if at least 50% of the value of a Fund's total assets at the close of each quarter of its taxable year is represented by interests in other regulated investment companies, such Fund may make an election to treat a proportionate amount of eligible foreign taxes as constituting a taxable distribution to each shareholder, which would, subject to certain limitations, generally allow the shareholder to either (i) credit that proportionate amount of taxes against U.S. Federal income tax liability as a foreign tax credit or (ii) to take that amount as an itemized deduction. Although in some cases the Fund may be able to apply for a refund of a portion of such taxes, the ability to successfully obtain such a refund may be uncertain.

A Note on the Tax-Exempt Municipal Funds. Dividends paid to shareholders of the PIMCO Short Term Municipal Bond Active Exchange- Traded Fund and PIMCO Intermediate Municipal Bond Active Exchange-Traded Fund (collectively, the "Tax-Exempt Municipal Funds") and derived from Municipal Bond interest are expected to be reported by the Tax-Exempt Municipal Funds as "exempt-interest dividends" and shareholders may generally exclude such dividends from gross income for federal income tax purposes. However, there can be no assurance that the Tax-Exempt Municipal Funds will satisfy the requirements to pay dividends eligible to be reported as "exempt-interest dividends" with respect to a particular taxable year. The federal tax exemption for "exempt-interest dividends" from Municipal Bonds does not necessarily result in the exemption of such dividends from state and local taxes. Each Tax-Exempt Municipal Fund may invest a portion of its assets in securities that generate income that is not exempt from federal or state income tax. Dividends derived from taxable interest or capital gains will be subject to federal income tax. The Tax-Exempt Municipal Funds seek to produce income that is generally exempt from federal income tax and will not benefit investors in tax-sheltered retirement plans or individuals not subject to federal income tax.

Any loss realized upon the sale or exchange of Tax-Exempt Municipal Fund shares with a tax holding period of six months or less will be disallowed to the extent of any distributions treated as exempt interest dividends with respect to such shares.

Foreign shareholders may be subject to U.S. tax withholding of 30% (or lower applicable treaty rate) on distributions from the Funds. Additionally, the Funds are required to withhold U.S. tax (at a 30% rate) on payments of taxable dividends and (effective January 1, 2019) redemption proceeds and certain capital gain dividends made to certain non-U.S. entities that fail to comply (or be deemed compliant) with extensive reporting and withholding requirements designed to inform the U.S. Department of the Treasury of U.S.-owned foreign investment accounts. Shareholders may be requested to provide additional information to enable the Funds to determine whether withholding is required.

This "Tax Consequences" section relates only to federal income tax; the consequences under other tax laws may differ. Shareholders should consult their tax advisors as to the possible application of foreign, state and local income tax laws to Fund dividends and capital distributions. Please see "Taxation" in the SAI for additional information regarding the tax aspects of investing in the Funds.

Most of these securities and investment techniques are discretionary, which means that PIMCO can decide whether to use them or not. This prospectus does not attempt to disclose all of the various types of securities and investment techniques that may be used by the Funds. As with any fund, investors in the Funds rely on the professional investment judgment and skill of PIMCO and the individual portfolio managers. Please see "Investment Objectives and Policies" in the SAI for more detailed information about the securities and investment techniques described in this section and about other strategies and techniques that may be used by the Funds.

Significant purchases and redemptions of its Creation Units for cash may adversely impact a Fund's portfolio management. For example, a Fund may be forced to sell a comparatively large portion of its portfolio to meet significant Creation Unit redemptions for cash, or hold a comparatively large portion of its portfolio in cash due to significant Creation Unit purchases for cash, in each case when the Fund otherwise would not seek to do so. Such transactions may cause Funds to make investment decisions at inopportune times or prices or miss attractive investment opportunities. Such transactions may also accelerate the realization of taxable income if sales of securities resulted in gains and the Fund redeems Creation Units for cash, or otherwise cause a Fund to perform differently than intended. Similarly, significant purchases of its Creation Units for cash may adversely affect a Fund's performance to the extent the Fund is delayed in investing new cash and, as a result, holds a proportionally larger cash position than under ordinary circumstances. While such risks may apply to Funds of any size, such risks are heightened in Funds with fewer assets under management. In addition, new Funds may not be able to fully implement their investment strategy immediately upon commencing investment operations, which could reduce investment performance.

Certain PIMCO-advised funds (the "PIMCO Funds of Funds") invest substantially all or a significant portion of their assets in other PIMCO-advised funds, including the Funds ("Underlying PIMCO Funds"). In some cases, the PIMCO Funds of Funds and certain funds managed by investment advisers affiliated with PIMCO ("Affiliated Funds of Funds") may be the predominant or sole shareholders of a particular Underlying PIMCO Fund. Investment decisions made with respect to the PIMCO Funds of Funds and Affiliated Funds of Funds could, under certain circumstances, negatively impact the Underlying PIMCO Funds with respect to the expenses and investment performance of the Underlying PIMCO Funds. For instance, large purchases or redemptions of exchange-traded shares of an Underlying PIMCO Fund by the PIMCO Funds of Funds and Affiliated Funds of Funds, whether as part of a reallocation or rebalancing strategy or otherwise, may indirectly result in the Underlying PIMCO Fund having to sell securities or invest cash when it otherwise would not do so. Such transactions could increase an Underlying PIMCO Fund's transaction costs and accelerate the realization of taxable income if sales of securities resulted in gains and the Fund redeems Creation Units for cash. Additionally, as the PIMCO Funds of Funds and Affiliated Funds of Funds may invest substantially all or a significant portion of their assets in Underlying PIMCO Funds, the Underlying PIMCO Funds may not acquire securities of other registered open-end investment companies in reliance on Section 12(d)(1)(F) or Section 12(d)(1)(G) of the 1940 Act, thus limiting the Underlying PIMCO Funds' investment flexibility.

The PIMCO Enhanced Low Duration Active Exchange-Traded Fund seeks total return. The total return sought by the Fund consists of both income earned on the Fund's investments and capital appreciation, if any, arising from increases in the market value of the Fund's holdings. Capital appreciation of fixed income securities generally results from decreases in market interest rates, foreign currency appreciation, or improving credit fundamentals for a particular market sector or security. The other Funds seek to provide income earned on the Fund's investments.

In selecting securities for a Fund, PIMCO develops an outlook for interest rates, currency exchange rates and the economy, analyzes credit and call risks, and uses other security selection techniques. The proportion of a Fund's assets committed to investment in securities with particular characteristics (such as quality, sector, interest rate or maturity) varies based on PIMCO's outlook for the U.S. economy and the economies of other countries in the world, the financial markets and other factors.

With respect to fixed income investing, PIMCO attempts to identify areas of the bond market that are undervalued relative to the rest of the market. PIMCO identifies these areas by grouping Fixed Income Instruments into sectors such as money markets, governments, corporates, mortgages, asset-backed and international. In seeking to identify undervalued currencies, PIMCO may consider many factors, including but not limited to longer-term analysis of relative interest rates, inflation rates, real exchange rates, purchasing power parity, trade account balances and current account balances, as well as other factors that influence exchange rates such as flows, market technical trends and government policies. Sophisticated proprietary software then assists in evaluating sectors and pricing specific

investments. Once investment opportunities are identified, PIMCO will shift assets among sectors depending upon changes in relative valuations, credit spreads and other factors. There is no guarantee that PIMCO's investment selection techniques will produce the desired results.

securities issued or guaranteed by the U.S. Government, its agencies or government-sponsored enterprises ("U.S. Government Securities");

corporate debt securities of U.S. and non-U.S. issuers, including convertible securities and corporate commercial paper;

structured notes, including hybrid or "indexed" securities and event-linked bonds;

repurchase agreements on Fixed Income Instruments and reverse repurchase agreements on Fixed Income Instruments;

debt securities issued by states or local governments and their agencies, authorities and other government-sponsored enterprises;

obligations of non-U.S. governments or their subdivisions, agencies and government-sponsored enterprises; and

Securities issued by U.S. Government agencies or government-sponsored enterprises may not be guaranteed by the U.S. Treasury.

Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates that incorporates a security's yield, coupon, final maturity and call features, among other characteristics. The longer a security's duration, the more sensitive it will be to changes in interest rates. Similarly, a fund with a longer average portfolio duration will be more sensitive to changes in interest rates than a fund with a shorter average portfolio duration. By way of example, the price of a bond fund with an average duration of eight years would be expected to fall approximately 8% if interest rates rose by one percentage point. Similarly, the price of a bond fund with an average duration of fifteen years would be expected to fall approximately 15% if interest rates rose by one percentage point. Conversely, the price of a bond fund with an average duration of negative three years would be expected to rise approximately 3% if interest rates rose by one percentage point. The maturity of a security, another commonly used measure of price sensitivity, measures only the time until final payment is due, whereas duration takes into account the pattern of all payments of interest and principal on a security over time, including how these payments are affected by prepayments and by changes in interest rates, as well as the time until an interest rate is reset (in the case of variable-rate securities). PIMCO uses an internal model for calculating duration, which may result in a different value for the duration of an index compared to the duration calculated by the index provider or another third party.

U.S. Government Securities are obligations of, or guaranteed by, the U.S. Government, its agencies or government-sponsored enterprises. The U.S. Government does not guarantee the NAV of a Fund's shares. U.S. Government Securities are subject to market and interest rate risk, as well as varying degrees of credit risk. Some U.S. Government Securities are issued or guaranteed by the U.S. Treasury and are supported by the full faith and credit of the United States. Other types of U.S. Government Securities are supported by the full faith and credit of the United States (but not issued by the U.S. Treasury). These securities may have less credit risk than U.S. Government Securities not supported by the full faith and credit of the United States. Such other types of U.S. Government Securities are: (1) supported by the ability of the issuer to borrow from the U.S. Treasury; (2) supported only by the credit of the issuing agency, instrumentality or government-sponsored corporation; or (3) supported by the United States in some other way. These securities may be subject to greater credit risk. U.S. Government Securities include zero coupon securities, which tend to be subject to greater market risk than interest-paying securities of similar maturities.

Securities issued by U.S. Government agencies or government-sponsored enterprises may not be guaranteed by the U.S. Treasury. Government National Mortgage Association ("GNMA"), a wholly owned U.S. Government corporation, is authorized to guarantee, with the full faith and credit of the U.S. Government, the timely payment of principal and interest on securities issued by institutions approved by GNMA and backed by pools of mortgages insured by the Federal Housing Administration or guaranteed by the Department of Veterans Affairs. Government-related guarantors (i.e., not backed by the full faith and credit of the U.S. Government) include the Federal National Mortgage Association ("FNMA") and the Federal Home Loan Mortgage Corporation ("FHLMC"). Pass-through securities issued by FNMA are guaranteed as to timely payment of principal and interest by FNMA but are not backed by the full faith and credit of the U.S. Government. FHLMC guarantees the timely payment of interest and ultimate collection of principal, but its participation certificates are not backed by the full faith and credit of the U.S. Government.

Municipal Bonds are generally issued by states, territories, possessions and local governments and their agencies, authorities and other instrumentalities. Municipal Bonds are subject to interest rate, credit and market risk, uncertainties related to the tax status of a Municipal Bond or the rights of investors invested in these securities. The ability of an issuer to make payments could be affected by litigation, legislation or other political events or the bankruptcy of the issuer. In addition, imbalances in supply and demand in the municipal market may result in a deterioration of liquidity and a lack of price transparency in the market. At certain times, this may

affect pricing, execution and transaction costs associated with a particular trade. The value of certain municipal securities, in particular general obligation debt, may also be adversely affected by rising health care costs, increasing unfunded pension liabilities, changes in accounting standards and by the phasing out of federal programs providing financial support. Lower rated Municipal Bonds are subject to greater credit and market risk than higher quality Municipal Bonds. The types of Municipal Bonds in which the Funds may invest include municipal lease obligations, municipal general obligation bonds, municipal essential service revenue bonds, municipal cash equivalents, and pre-refunded and escrowed to maturity Municipal Bonds. The Funds may also invest in industrial development bonds, which are Municipal Bonds issued by a government agency on behalf of a private sector company and, in most cases, are not backed by the credit of the issuing municipality and may therefore involve more risk. The Funds may also invest in securities issued by entities whose underlying assets are Municipal Bonds.

Pre-refunded Municipal Bonds are tax-exempt bonds that have been refunded to a call date on or before the final maturity of principal and remain outstanding in the municipal market. The payment of principal and interest of the pre-refunded Municipal Bonds held by a Fund is funded from securities in a designated escrow account that holds U.S. Treasury securities or other obligations of the U.S. Government (including its agencies and instrumentalities ("Agency Securities")). As the payment of principal and interest is generated from securities held in a designated escrow account, the pledge of the municipality has been fulfilled and the original pledge of revenue by the municipality is no longer in place. The escrow account securities pledged to pay the principal and interest of the pre-refunded Municipal Bond do not guarantee the price movement of the bond before maturity. Investment in pre-refunded Municipal Bonds held by a Fund may subject the Fund to interest rate risk, market risk and credit risk. In addition, while a secondary market exists for pre-refunded Municipal Bonds, if a Fund sells pre-refunded Municipal Bonds prior to maturity, the price received may be more or less than the original cost, depending on market conditions at the time of sale.

Certain Funds may invest in trust certificates issued in tender option bond programs. In these programs, a trust typically issues two classes of certificates and uses the proceeds to purchase municipal securities having relatively long maturities and bearing interest at a fixed interest rate substantially higher than prevailing short-term tax-exempt rates. There is a risk that a Fund investing in a tender option bond program will not be considered the owner of a tender option bond for federal income tax purposes, and thus will not be entitled to treat such interest as exempt from federal income tax. Certain tender option bonds may be illiquid or may become illiquid as a result of, among other things, a credit rating downgrade, a payment default or a disqualification from tax-exempt status. A Fund's investment in the securities issued by a tender option bond trust may involve greater risk and volatility than an investment in a fixed rate bond, and the value of such securities may decrease significantly when market interest rates increase. Tender option bond trusts could be terminated due to market, credit or other events beyond a Fund's control, which could require the Fund to dispose of portfolio investments at inopportune times and prices. A Fund may use a tender option bond program as a way of achieving leverage in its portfolio, in which case the Fund will be subject to leverage risk.

In December 2013, regulators finalized rules implementing Section 619 (the "Volcker Rule") and Section 941 (the "Risk Retention Rules") of the Dodd-Frank Wall Street Reform and Consumer Protection Act. Both the Volcker Rule and the Risk Retention Rules apply to tender option bond programs and require that such programs be restructured. In particular, these rules preclude banking entities from: (i) sponsoring or acquiring interests in the trusts used to hold a Municipal Bond in the creation of tender option bond trusts; and (ii) continuing to service or maintain relationships with existing programs involving such trusts to the same extent and in the same capacity as existing programs. At this time, the full impact of these rules is not certain; however, in response to these rules, industry participants are continuing to explore various structuring alternatives for tender option bond programs. Because of the important role that tender option bond programs play in the Municipal Bond market, it is possible that implementation of these rules and any resulting impact may adversely impact the Municipal Bond market. For example, as a result of the implementation of these rules, the Municipal Bond market may experience reduced demand or liquidity and increased financing costs.

The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund may invest in high yield securities. Securities rated lower than Baa by Moody's, or equivalently rated by S&P or Fitch, are sometimes referred to as "high yield securities" or "junk bonds." Investing in these securities involves special risks in addition to the risks associated with investments in higher-rated fixed income securities. While offering a greater potential opportunity for capital appreciation and higher yields, high yield securities typically entail greater potential price volatility and may be less liquid than higher-rated securities. High yield securities may be regarded as predominately speculative with respect to the issuer's continuing ability to meet principal and interest payments. They may also be more susceptible to real or perceived adverse economic and competitive industry conditions than higher-rated securities. Certain Funds may invest in securities that are in default with respect to the payment of interest or repayment of principal, or present an imminent risk of default with respect to such payments. Issuers of securities in default may fail to resume principal or interest payments, in which case a Fund may lose its entire investment.

Mortgage-related securities include mortgage pass-through securities, collateralized mortgage obligations ("CMOs"), commercial mortgage-backed securities, mortgage dollar rolls, CMO residuals, stripped mortgage-backed securities ("SMBSs") and other securities that directly or indirectly represent a participation in, or are secured by and payable from, mortgage loans on real property. A to-be-announced ("TBA") transaction is a method of trading mortgage-backed securities. In a TBA transaction, the buyer and seller agree upon general trade parameters such as agency, settlement date, par amount and price. The actual pools delivered generally are determined two days prior to the settlement date.

The value of some mortgage-or asset-backed securities may be particularly sensitive to changes in prevailing interest rates. Early repayment of principal on some mortgage-related securities may expose a Fund to a lower rate of return upon reinvestment of principal. When interest rates rise, the value of a mortgage-related security generally will decline; however, when interest rates are declining, the value of mortgage-related securities with prepayment features may not increase as much as other fixed income securities. The rate of prepayments on underlying mortgages will affect the price and volatility of a mortgage-related security, and may shorten or extend the effective maturity of the security beyond what was anticipated at the time of purchase. If unanticipated rates of prepayment on underlying mortgages increase the effective maturity of a mortgage-related security, the volatility of the security can be expected to increase. The value of these securities may fluctuate in response to the market's perception of the creditworthiness of the issuers. See "Extension Risk" and "Prepayment Risk" below. The value of these securities may also fluctuate in response to the market's perception of the creditworthiness of the issuers. Additionally, although mortgages and mortgage-related securities are generally supported by some form of government or private guarantee and/or insurance, there is no assurance that guarantors or insurers will meet their obligations.

Extension Risk. Mortgage-related and other asset-backed securities are subject to Extension Risk, which is the risk that the issuer of such a security pays back the principal of such an obligation later than expected. This may occur when interest rates rise. This may negatively affect Fund returns, as the value of the security decreases when principal payments are made later than expected. In addition, because principal payments are made later than expected, the Fund may be prevented from investing proceeds it would otherwise have received at a given time at the higher prevailing interest rates.

Prepayment Risk. Mortgage-related and other asset-backed securities are subject to Prepayment Risk, which is the risk that the issuer of such a security pays back the principal of such an obligation earlier than expected (due to the sale of the underlying property, refinancing, or foreclosure). This may occur when interest rates decline. Prepayment may expose the Fund to a lower rate of return upon reinvestment of principal. Also, if a security subject to prepayment has been purchased at a premium, the value of the premium would be lost in the event of prepayment.

One type of SMBS has one class receiving all of the interest from the mortgage assets (the interest-only, or "IO" class), while the other class will receive all of the principal (the principal-only, or "PO" class). The yield to maturity on an IO class is extremely sensitive to the rate of principal payments (including prepayments) on the underlying mortgage assets, and a rapid rate of principal payments may have a material adverse effect on a Fund's yield to maturity from these securities. The PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund and PIMCO Enhanced Short Maturity Active Exchange-Traded Fund may invest up to 5% of their respective total assets in any combination of mortgage-related or other asset-backed IO, PO or inverse floater securities.

Certain Funds may invest in each of collateralized bond obligations ("CBOs"), collateralized loan obligations ("CLOs"), other collateralized debt obligations ("CDOs") and other similarly structured securities. CBOs, CLOs and other CDOs are types of asset-backed securities. A CBO is a trust which is backed by a diversified pool of high-risk, below investment grade fixed income securities. A CLO is a trust typically collateralized by a pool of loans, which may include, among others, domestic and foreign senior secured loans, senior unsecured loans, and subordinate corporate loans, including loans that may be rated below investment grade or equivalent unrated loans. Other CDOs are trusts backed by other types of assets representing obligations of various parties. Certain Funds may invest in other asset-backed securities that have been offered to investors.

Each Fund may be subject to the risk that the returns of the Fund will decline during periods of falling interest rates because the Fund may have to reinvest the proceeds from matured, traded or called debt obligations at interest rates below the Fund's current earnings rate. For instance, when interest rates decline, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, thereby forcing the Fund to invest in lower-yielding securities. A Fund also may choose to sell higher-yielding portfolio securities and to purchase lower-yielding securities to achieve greater portfolio diversification, because the Fund's portfolio manager believes the current holdings are overvalued or for other investment-related reasons. A decline in the returns received by a Fund from its investments is likely to have an adverse effect on the Fund's NAV, yield and total return.

To the extent that a Fund focuses its investments in a particular sector, the Fund may be susceptible to loss due to adverse developments affecting that sector. These developments include, but are not limited to, governmental regulation; inflation; rising interest rates; cost increases in raw materials, fuel and other operating expenses; technological innovations that may render existing products and equipment obsolete; competition from new entrants; high research and development costs; increased costs associated with compliance with environmental or other governmental regulations; and other economic, business or political developments specific to that sector. Furthermore, a Fund may invest a substantial portion of its assets in companies in related sectors that may share common characteristics, are often subject to similar business risks and regulatory burdens, and whose securities may react similarly to the types of developments described above, which will subject the Fund to greater risk. A Fund also will be subject to focused investment risk to the extent that it invests a substantial portion of its assets in a particular issuer, market, asset class, country or geographic region.

Corporate debt securities are subject to the risk of the issuer's inability to meet principal and interest payments on the obligation and may also be subject to price volatility due to such factors as interest rate sensitivity, market perception of the creditworthiness of the issuer and general market liquidity. When interest rates rise, the value of corporate debt securities can be expected to decline. Debt securities with longer maturities tend to be more sensitive to interest rate movements than those with shorter

maturities. In addition, certain corporate debt securities may be highly customized and as a result may be subject to, among others, liquidity and pricing transparency risks.

There are two common types of bank capital: Tier I and Tier II. Bank capital is generally, but not always, of investment grade quality. Tier I securities often take the form of trust preferred securities. Tier II securities are commonly thought of as hybrids of debt and preferred securities, are often perpetual (with no maturity date), callable and, under certain conditions, allow for the issuer bank to withhold payment of interest until a later date.

Trust preferred securities have the characteristics of both subordinated debt and preferred securities. The primary advantage of the structure of trust preferred securities is that they are treated by the financial institution as debt securities for tax purposes and as equity for the calculation of capital requirements. Trust preferred securities typically bear a market rate coupon comparable to interest rates available on debt of a similarly rated issuer. Typical characteristics include long-term maturities, early redemption by the issuer, periodic fixed or variable interest payments, and maturities at face value. The market value of trust preferred securities may be more volatile than those of conventional debt securities. There can be no assurance as to the liquidity of trust preferred securities and the ability of holders, such as a Fund, to sell their holdings.

The PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund and PIMCO Enhanced Short Maturity Active Exchange-Traded Fund may invest in fixed- and floating-rate loans, which investments generally will be in the form of loan participations and assignments of all or portions of such loans. Participations and assignments involve special types of risk, including extension risk, prepayment risk, credit risk, interest rate risk, liquidity risk, and the risks of being a lender. Loans are subject to the risk that scheduled interest or principal payments will not be made in a timely manner or at all, either of which may adversely affect the value of the loan. In addition, the collateral underlying a loan may be unavailable or insufficient to satisfy a borrower's obligation, and a Fund could become part owner of any collateral if a loan is foreclosed, subjecting the Fund to costs associated with owning and disposing of the collateral. If a Fund purchases a participation, it may only be able to enforce its rights through the lender, and may assume the credit risk of the lender in addition to the borrower.

Variable and floating rate securities are securities that pay interest at rates that adjust whenever a specified interest rate changes and/or that reset on predetermined dates (such as the last day of a month or a calendar quarter). The PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund, PIMCO Enhanced Short Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund may invest in floating rate debt instruments ("floaters") and engage in credit spread trades. Variable and floating rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. Conversely, floating rate securities will not generally increase in value if interest rates decline. The PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund and PIMCO Enhanced Short Maturity Active Exchange-Traded Fund may also invest in inverse floating rate debt instruments ("inverse floaters"). An inverse floater may exhibit greater price volatility than a fixed rate obligation of similar credit quality. The PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund and PIMCO Enhanced Short Maturity Active Exchange-Traded Fund may invest up to 5% of their respective total assets in any combination of mortgage-related or other asset-backed IO, PO or inverse floater securities. Additionally, a Fund may also invest, without limitation, in residual interest bonds. Residual interest bonds are a type of inverse floater. See "Municipal Bonds."

Inflation-indexed bonds (other than municipal inflation-indexed bonds and certain corporate inflation-indexed bonds, which are more fully described below) are fixed income securities whose principal value is periodically adjusted according to the rate of inflation. If the index measuring inflation falls, the principal value of inflation-indexed bonds (other than municipal inflation-indexed bonds and certain corporate inflation-indexed bonds) will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced. Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of TIPS. For bonds that do not provide a similar guarantee, the adjusted principal value of the bond repaid at maturity may be less than the original principal. TIPS may also be divided into individual zero-coupon instruments for each coupon or principal payment (known as "iSTRIPS"). An iSTRIP of the principal component of a TIPS issue will retain the embedded deflation floor that will allow the holder of the security to receive the greater of the original principal or inflation-adjusted principal value at maturity. iSTRIPS may be less liquid than conventional TIPS because they are a small component of the TIPS market.

Municipal inflation-indexed securities are municipal bonds that pay coupons based on a fixed rate plus the Consumer Price Index for All Urban Consumers ("CPI"). With regard to municipal inflation-indexed bonds and certain corporate inflation-indexed bonds, the inflation adjustment is reflected in the semi-annual coupon payment. As a result, the principal value of municipal inflation-indexed bonds and such corporate inflation-indexed bonds does not adjust according to the rate of inflation. At the same time, the value of municipal inflation-indexed securities and such corporate inflation-indexed securities generally will not increase if the rate of inflation decreases. Because municipal inflation-indexed securities and corporate inflation-indexed securities are a small component of the municipal bond and corporate bond markets, respectively, they may be less liquid than conventional municipal and corporate bonds.

leading to a decrease in value of inflation-indexed bonds. Any increase in the principal amount of an inflation-indexed bond will be considered taxable ordinary income, even though investors do not receive their principal until maturity.

The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund may obtain event-linked exposure by investing in "event-linked bonds" or "event-linked swaps" or by implementing "event-linked strategies." Event-linked exposure results in gains or losses that typically are contingent, or formulaically related to defined trigger events. Examples of trigger events include hurricanes, earthquakes, weather-related phenomena, or statistics related to such events. Some event-linked bonds are commonly referred to as "catastrophe bonds." If a trigger event occurs, a Fund may lose a portion or its entire principal invested in the bond or notional amount on a swap. Event-linked exposure often provides for an extension of maturity to process and audit loss claims where a trigger event has, or possibly has, occurred. An extension of maturity may increase volatility. Event-linked exposure may also expose a Fund to certain unanticipated risks including counterparty risk, adverse regulatory or jurisdictional interpretations, and adverse tax consequences. Event-linked exposures may also be subject to liquidity risk.

Common stock represents equity ownership in a company and typically provides the common stockholder the power to vote on certain corporate actions, including the election of the company's directors. Common stockholders participate in company profits through dividends and, in the event of bankruptcy, distributions, on a pro-rata basis after other claims are satisfied. Many factors affect the value of common stock, including earnings, earnings forecasts, corporate events and factors impacting the issuer's industry and the market generally. Common stock generally has the greatest appreciation and depreciation potential of all corporate securities.

The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund may invest in convertible securities and equity securities, as well as securities related to equities. Equity-related securities include securities having an equity component (e.g., hybrids, bank capital) and equity derivatives. These Funds may not purchase common stock, but this limitation does not prevent the Funds from holding common stock obtained through the conversion of convertible securities or common stock that is received as part of a corporate reorganization or debt restructuring (for example, as may occur during bankruptcies or distressed situations).

The PIMCO Enhanced Low Duration Active Exchange-Traded Fund may invest a de minimis amount of its total assets (i.e., less than 5% of its total assets) in preferred securities, convertible securities and other equity-related securities.

Convertible securities are generally preferred securities and other securities, including fixed income securities and warrants, that are convertible into or exercisable for common stock at a stated price or rate. The price of a convertible security will normally vary in some proportion to changes in the price of the underlying common stock because of this conversion or exercise feature. However, the value of a convertible security may not increase or decrease as rapidly as the underlying common stock. A convertible security will normally also provide income and is subject to interest rate risk. Convertible securities may be lower-rated securities subject to greater levels of credit risk. A Fund may be forced to convert a security before it would otherwise choose, which may have an adverse effect on the Fund's ability to achieve its investment objective.

"Synthetic" convertible securities are selected based on the similarity of their economic characteristics to those of a traditional convertible security due to the combination of separate securities that possess the two principal characteristics of a traditional convertible security, i.e., an income-producing security ("income-producing component") and the right to acquire an equity security ("convertible component"). The income-producing component is achieved by investing in non-convertible, income-producing securities such as bonds, preferred securities and money market instruments, which may be represented by derivative instruments. The convertible component is achieved by investing in securities or instruments such as warrants or options to buy common stock at a certain exercise price, or options on a stock index. A simple example of a synthetic convertible security is the combination of a traditional corporate bond with a warrant to purchase equity securities of the issuer of the bond. A Fund may also purchase synthetic securities created by other parties, typically investment banks, including convertible structured notes. The income-producing and convertible components of a synthetic convertible security may be issued separately by different issuers and at different times.

Preferred and other senior securities generally entitle the holder to receive, in preference to the holders of other securities such as common stocks, dividends and a fixed share of the proceeds resulting from a liquidation of the company. Preferred and other senior securities may pay fixed or adjustable rates of return. Preferred and other senior securities are subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company's preferred and other senior securities generally pay dividends only after the company makes required payments to holders of its bonds and other debt. For this reason, the value of preferred and other senior securities will usually react more strongly than bonds and other debt to actual or perceived changes in the company's financial condition or prospects. In addition, preferred and other senior securities often have special redemption rights allowing issuers to redeem such securities at par earlier than scheduled. If these rights are exercised, a Fund may have to reinvest proceeds in less attractive securities.

Among other risks described in this prospectus, the following issues are particularly associated with investments in preferred and other senior securities.

Deferral and Omission of Distributions. Preferred and other senior securities may include features permitting or requiring the issuer to defer or omit distributions. Among other things, such deferral or omission may result in adverse tax consequences for a Fund.

Limited Voting Rights. Preferred and other senior securities generally do not have voting rights with respect to the issuer unless dividends have been in arrears for certain specified periods of time.

In the future, preferred or other senior securities may be offered with features different from those described above, and as such, may entail different risks. Over longer periods of time, certain types of preferred or other senior securities may become more scarce or less liquid as a result of legislative changes. Such events may result in losses to a Fund as the prices of securities it holds may be negatively affected. Revisions to bank capital requirements by international regulatory bodies, to the extent they are adopted in the United States, may also negatively impact the market for certain preferred or senior securities.

While some countries or companies may be regarded as favorable investments, pure fixed income opportunities may be unattractive or limited due to insufficient supply, or legal or technical restrictions. In such cases, subject to its applicable investment restrictions, a Fund may consider convertible securities or equity securities to gain exposure to such investments.

At times, in connection with the restructuring of a preferred security or Fixed Income Instrument either outside of bankruptcy court or in the context of bankruptcy court proceedings, a Fund may determine or be required to accept equity securities, such as common stocks, in exchange for all or a portion of a preferred security or Fixed Income Instrument. Depending upon, among other things, PIMCO's evaluation of the potential value of such securities in relation to the price that could be obtained by a Fund at any given time upon sale thereof, a Fund may determine to hold such securities in its portfolio.

Equity securities generally have greater price volatility than fixed income securities. The market price of equity securities owned by a Fund may go up or down, sometimes rapidly or unpredictably. Equity securities may decline in value due to factors affecting equity securities markets generally or particular industries represented in those markets. The value of an equity security may also decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods or services.

The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund may invest in securities and instruments that are economically tied to foreign (non-U.S.) countries. The PIMCO Enhanced Short Maturity Active Exchange-Traded Fund may invest in U.S. dollar-denominated securities and instruments that are economically tied to foreign (non-U.S.) countries. PIMCO generally considers an instrument to be economically tied to a non-U.S. country if the issuer is a foreign (non-U.S.) government (or any political subdivision, agency, authority or instrumentality of such government), or if the issuer is organized under the laws of a non-U.S. country. In the case of money market instruments other than commercial paper and certificates of deposit, such instruments will be considered economically tied to a non-U.S. country if the issuer of such money market instrument is organized under the laws of a non-U.S. country. In the case of commercial paper and certificates of deposit, such instruments will be considered economically tied to a non-U.S. country if the "country of exposure" of such instrument is a non-U.S. country, as determined by the criteria set forth below.

With respect to derivative instruments, which each Fund (except the PIMCO Enhanced Short Maturity Active Exchange- Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund) may utilize, PIMCO generally considers such instruments to be economically tied to non-U.S. countries if the underlying assets are foreign currencies (or baskets or indexes of such currencies), or instruments or securities that are issued by foreign governments or issuers organized under the laws of a non-U.S. country (or if the underlying assets are money market instruments other than commercial paper and certificates of deposit, the issuer of such money market instrument is organized under the laws of a non-U.S. country or, in the case of underlying assets that are commercial paper or certificates of deposit, if the "country of exposure" of such money market instrument is a non-U.S. country). A security's "country of exposure" is determined by PIMCO using certain factors provided by a third-party analytical service provider. The factors are applied in order such that the first factor to result in the assignment of a country determines the "country of exposure." Both the factors and the order in which they are applied may change in the discretion of PIMCO. The current factors, listed in the order in which they are applied, are: (i) if an asset-backed or other collateralized security, the country in which the collateral backing the security is located; (ii) the "country of risk" of the issuer; (iii) if the security is guaranteed by the government of a country (or any political subdivision, agency, authority or instrumentality of such government), the country of the government or instrumentality providing the guarantee; (iv) the "country of risk" of the issuer's ultimate parent; or (v) the country where the issuer is organized or incorporated under the laws thereof. "Country of risk" is a separate four-part test determined by the following factors, listed in order of importance: (i) management location; (ii) country of primary listing; (iii) sales or revenue attributable to the country; and (iv) reporting currency of the issuer. Further, where a derivative instrument is exposed to an index, PIMCO generally considers the derivative to be economically tied to each country represented by the components of the underlying index pursuant to the criteria set forth in the preceding sentence.

Investing in foreign (non-U.S.) securities involves special risks and considerations not typically associated with investing in U.S. securities. Investors should consider carefully the substantial risks involved for Funds that invest in securities issued by foreign companies and governments of foreign countries. These risks include: differences in accounting, auditing and financial reporting standards; generally higher commission rates on foreign portfolio transactions; the possibility of nationalization, expropriation or confiscatory taxation; adverse changes in investment or exchange control regulations; and political instability. Individual foreign economies may differ favorably or unfavorably from the U.S. economy in such respects as growth of gross domestic product, rates of inflation, capital reinvestment, resources, self-sufficiency and balance of payments position. The securities markets, values of securities, yields and risks associated with foreign (non-U.S.) securities markets may change independently of each other. Also, foreign (non-U.S.) securities and dividends and interest payable on those securities may be subject to foreign taxes, including taxes withheld from payments on those securities. Foreign (non-U.S.) securities often trade with less frequency and volume than domestic securities and therefore may exhibit greater price volatility.

Investments in foreign (non-U.S.) securities may also involve higher custodial costs than domestic investments and additional transaction costs with respect to foreign currency conversions. Changes in foreign exchange rates also will affect the value of securities denominated or quoted in foreign currencies.

Certain Funds also may invest in sovereign debt issued by governments, their agencies or instrumentalities, or other government-related entities. Holders of sovereign debt may be requested to participate in the rescheduling of such debt and to extend further loans to governmental entities. In addition, there is no bankruptcy proceeding by which defaulted sovereign debt may be collected.

Emerging Market Securities. The PIMCO Active Bond Exchange-Traded Fund may invest up to 15% of its total assets in securities and instruments that are economically tied to emerging market countries. The PIMCO Enhanced Low Duration Active Exchange-Traded Fund may invest up to 10% of its total assets in securities and instruments that are economically tied to emerging market countries. The PIMCO Enhanced Short Maturity Active Exchange-Traded Fund may invest up to 5% of its total assets in U.S. dollar-denominated securities and instruments that are economically tied to developing (or "emerging market") countries. PIMCO generally considers an instrument to be economically tied to an emerging market country if: the issuer is organized under the laws of an emerging market country; the currency of settlement of the security is a currency of an emerging market country; the security is guaranteed by the government of an emerging market country (or any political subdivision, agency, authority or instrumentality of such government); for an asset-backed or other collateralized security, the country in which the collateral backing the security is located is an emerging market country; or the security's "country of exposure" is an emerging market country, as determined by the criteria set forth below. With respect to derivative instruments for each Fund (except the PIMCO Enhanced Short Maturity Active Exchange-Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund), PIMCO generally considers such instruments to be economically tied to emerging market countries if the underlying assets are currencies of emerging market countries (or baskets or indexes of such currencies), or instruments or securities that are issued or guaranteed by governments of emerging market countries or by entities organized under the laws of emerging market countries or if an instrument's "country of exposure" is an emerging market country. A security's "country of exposure" is determined by PIMCO using certain factors provided by a third-party analytical service provider. The factors are applied in order such that the first factor to result in the assignment of a country determines the "country of exposure." Both the factors and the order in which they are applied may change in the discretion of PIMCO. The current factors, listed in the order in which they are applied, are: (i) if an asset-backed or other collateralized security, the country in which the collateral backing the security is located; (ii) the "country of risk" of the issuer; (iii) if the security is guaranteed by the government of a country (or any political subdivision, agency, authority or instrumentality of such government), the country of the government or instrumentality providing the guarantee; (iv) the "country of risk" of the issuer's ultimate parent; or (v) the country where the issuer is organized or incorporated under the laws thereof. "Country of risk" is a separate four-part test determined by the following factors, listed in order of importance: (i) management location; (ii) country of primary listing; (iii) sales or revenue attributable to the country; and (iv) reporting currency of the issuer. PIMCO has broad discretion to identify countries that it considers to qualify as emerging markets. In making investments in emerging market securities, a Fund emphasizes those countries with relatively low gross national product per capita and with the potential for rapid economic growth. Emerging market countries are generally located in Asia, Africa, the Middle East, Latin America and Eastern Europe. PIMCO will select the country and currency composition based on its evaluation of relative interest rates, inflation rates, exchange rates, monetary and fiscal policies, trade and current account balances, legal and political developments and any other specific factors it believes to be relevant.

Additional risks of emerging market securities may include: greater social, economic and political uncertainty and instability; more substantial governmental involvement in the economy; less governmental supervision and regulation; unavailability of currency hedging techniques; companies that are newly organized and small; differences in auditing and financial reporting standards, which may result in unavailability of material information about issuers; and less developed legal systems. In addition, emerging securities markets may have different clearance and settlement procedures, which may be unable to keep pace with the volume of securities transactions or otherwise make it difficult to engage in such transactions. Settlement problems may cause a Fund to miss attractive investment opportunities, hold a portion of its assets in cash pending investment, or be delayed in disposing of a portfolio security. Such a delay could result in possible liability to a purchaser of the security.

The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund invest directly in foreign (non-U.S.)

currencies or in securities that trade in, or receive revenues in, foreign (non-U.S.) currencies and will be subject to currency risk. Foreign currency exchange rates may fluctuate significantly over short periods of time. They generally are determined by supply and demand in the foreign exchange markets and the relative merits of investments in different countries, actual or perceived changes in interest rates and other complex factors. Currency exchange rates also can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign governments or central banks, or by currency controls or political developments. Currencies in which a Fund's assets are denominated may be devalued against the U.S. dollar, resulting in a loss to the Fund.

Foreign Currency Transactions. The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund may invest in securities denominated in foreign (non-U.S.) currencies, engage in foreign currency transactions on a spot (cash) basis, enter into forward foreign currency exchange contracts and invest in foreign currency futures contracts and options on foreign currencies and futures. A forward foreign currency exchange contract, which involves an obligation to purchase or sell a specific currency at a future date at a price set at the time of the contract, reduces a Fund's exposure to changes in the value of the currency it will deliver and increases its exposure to changes in the value of the currency it will receive for the duration of the contract. Certain foreign currency transactions may also be settled in cash rather than the actual delivery of the relevant currency. The effect on the value of a Fund is similar to selling securities denominated in one currency and purchasing securities denominated in another currency. Foreign currency transactions, like currency exchange rates, can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign governments or central banks, or by currency controls or political developments. Such events may prevent or restrict a Fund's ability to enter into foreign currency transactions, force the Fund to exit a foreign currency transaction at a disadvantageous time or price or result in penalties for the Fund, any of which may result in a loss to the Fund. A contract to sell a foreign currency would limit any potential gain which might be realized if the value of the hedged currency increases. A Fund may enter into these contracts to hedge against foreign exchange risk, to increase exposure to a foreign currency or to shift exposure to foreign currency fluctuations from one currency to another. Suitable hedging transactions may not be available in all circumstances and there can be no assurance that a Fund will engage in such transactions at any given time or from time to time. Also, such transactions may not be successful and may eliminate any chance for a Fund to benefit from favorable fluctuations in relevant foreign currencies. A Fund may use one currency (or a basket of currencies) to hedge against adverse changes in the value of another currency (or a basket of currencies) when exchange rates between the two currencies are positively correlated. A Fund will segregate or "earmark" assets determined to be liquid by PIMCO in accordance with the procedures established by the Board of Trustees (or, as permitted by applicable law, enter into certain offsetting positions) to cover its obligations under forward foreign currency exchange contracts.

Redenomination. Continuing uncertainty as to the status of the euro and the European Monetary Union (the "EMU") has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU could have significant adverse effects on currency and financial markets and on the values of a Fund's portfolio investments. If one or more EMU countries were to stop using the euro as its primary currency, a Fund's investments in such countries may be redenominated into a different or newly adopted currency. As a result, the value of those investments could decline significantly and unpredictably. In addition, securities or other investments that are redenominated may be subject to currency risk, liquidity risk and risk of improper valuation to a greater extent than similar investments currently denominated in euros. To the extent a currency used for redenomination purposes is not specified in respect of certain EMU-related investments, or should the euro cease to be used entirely, the currency in which such investments are denominated may be unclear, making such investments particularly difficult to value or dispose of. A Fund may incur additional expenses to the extent it is required to seek judicial or other clarification of the denomination or value of such securities.

There can be no assurance that if a Fund earns income or capital gains in a non-U.S. country or PIMCO otherwise seeks to withdraw the Fund's investments from a given country, capital controls imposed by such country will not prevent, or cause significant expense in, doing so.

Each Fund may enter into repurchase agreements, in which the Fund purchases a security from a bank or broker-dealer, which agrees to repurchase the security at the Fund's cost plus interest within a specified time. If the party agreeing to repurchase should default, the Fund will seek to sell the securities which it holds. This could involve procedural costs or delays in addition to a loss on the securities if their value should fall below their repurchase price. Repurchase agreements maturing in more than seven days and which may not be terminated within seven days at approximately the amount at which a Fund has valued the agreements are considered illiquid securities.

Each Fund may enter into reverse repurchase agreements and dollar rolls, subject to the Fund's limitations on borrowings. A reverse repurchase agreement involves the sale of a security by a Fund and its agreement to repurchase the instrument at a specified time and price. A dollar roll is similar except that the counterparty is not obligated to return the same securities as those originally sold by the Fund but only securities that are "substantially identical." Reverse repurchase agreements and dollar rolls may be considered borrowing for some purposes. A Fund will segregate or "earmark" assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees to cover its obligations under reverse repurchase agreements and dollar rolls. Reverse repurchase agreements, dollar rolls and other forms of borrowings may create leveraging risk for a Fund.

Each Fund may borrow money to the extent permitted under the 1940 Act. This means that, in general, a Fund may borrow money from banks for any purpose in an amount up to 1/3 of the Fund's total assets, less all liabilities and indebtedness not represented by senior securities. A Fund may also borrow money for temporary administrative purposes in an amount not to exceed 5% of the Fund's total assets. In addition, a Fund may borrow from certain other PIMCO funds in inter-fund lending transactions to the extent permitted by an exemptive order from the SEC.

Each Fund (except the PIMCO Enhanced Short Maturity Active Exchange-Traded Fund, PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund) may, but is not required to, use derivative instruments for risk management purposes or as part of its investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate or index, and may relate to stocks, bonds, interest rates, spreads between different interest rates, currencies or currency exchange rates, commodities, and related indexes. Examples of derivative instruments include options contracts, futures contracts, options on futures contracts and swap agreements (including, but not limited to, credit default swaps and swaps on ETFs). Each Fund may invest some or all of its assets in derivative instruments, subject to the Fund's objective and policies. A portfolio manager may decide not to employ any of these strategies and there is no assurance that any derivatives strategy used by a Fund will succeed. A description of these and other derivative instruments that the Funds may use are described under "Investment Objectives and Policies" in the SAI.

A Fund's use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other more traditional investments. Certain derivative transactions may have a leveraging effect on a Fund. For example, a small investment in a derivative instrument may have a significant impact on a Fund's exposure to interest rates, currency exchange rates or other investments. As a result, a relatively small price movement in a derivative instrument may cause an immediate and substantial loss or gain. A Fund may engage in such transactions regardless of whether the Fund owns the asset, instrument or components of the index underlying the derivative instrument. A Fund may invest a significant portion of its assets in these types of instruments. If it does, the Fund's investment exposure could far exceed the value of its portfolio securities and its investment performance could be primarily dependent upon securities it does not own. A description of various risks associated with particular derivative instruments is included in "Investment Objectives and Policies" in the SAI. The following provides a more general discussion of important risk factors relating to all derivative instruments that may be used by the Funds.

CPI Swap. A CPI swap is a fixed maturity, OTC derivative transaction in which the investor receives the "realized" rate of inflation as measured by the CPI over the life of the swap. The investor in turn pays a fixed annualized rate over the life of the swap. This fixed rate is often referred to as the "breakeven inflation" rate and is generally representative of the difference between treasury yields and TIPS yields of similar maturities at the initiation of the swap. CPI swaps are typically in "bullet" format, where all cash flows are exchanged at maturity. In addition to counterparty risk, CPI swaps are also subject to inflation risk, where the swap can potentially lose value if the realized rate of inflation over the life of the swap is less than the fixed market implied inflation rate (fixed breakeven rate) that the investor agrees to pay at the initiation of the swap.

Management Risk. Derivative products are highly specialized instruments that require investment techniques and risk analyses different from those associated with stocks and bonds. The use of a derivative requires an understanding not only of the underlying instrument but also of the derivative itself, without the benefit of observing the performance of the derivative under all possible market conditions.

Credit Risk. The use of certain derivative instruments involves the risk that a loss may be sustained as a result of the failure of another party to the contract (usually referred to as a "counterparty") to make required payments or otherwise comply with the contract's terms. Additionally, a short position in a credit default swap could result in losses if the Fund does not correctly evaluate the creditworthiness of the company on which the credit default swap is based.

Liquidity Risk. Liquidity risk exists when a particular derivative instrument is difficult to purchase or sell. If a derivative transaction is particularly large or if the relevant market is illiquid (as is the case with many privately negotiated derivatives), it may not be possible to initiate a transaction or liquidate a position at an advantageous time or price.

Leverage Risk. Because many derivatives have a leverage component, adverse changes in the value or level of the underlying asset, reference rate or index could result in a loss substantially greater than the amount invested in the derivative itself. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. When a Fund uses derivatives for leverage, investments in that Fund will tend to be more volatile, resulting in larger gains or losses in response to market changes. To limit leverage risk, each Fund will segregate or "earmark" assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees (or, as permitted by applicable regulation, enter into certain offsetting positions) to cover its obligations under derivative instruments.

Lack of Availability. Because the markets for certain derivative instruments (including markets located in foreign countries) are relatively new and still developing, suitable derivatives transactions may not be available in all circumstances for risk management or other purposes. Upon the expiration of a particular contract, a portfolio manager may wish to retain a Fund's position in the derivative instrument by entering into a similar contract, but may be unable to do so if the counterparty to the original contract is unwilling to enter into the new contract and no other suitable counterparty can be found. There is no assurance that a Fund will engage in derivatives transactions at any time or from time to time. A Fund's ability to use derivatives may also be limited by certain regulatory and tax considerations.

based because the fund's return is net of fees and expenses. In this regard, many of the Funds offered in this prospectus seek to achieve their investment objectives, in part, by investing in derivatives positions that are designed to closely track the performance (or inverse performance) of an index on a daily basis. However, the overall investment strategies of these Funds are not designed or expected to produce returns which replicate the performance (or inverse performance) of the particular index, and the degree of variation could be substantial, particularly over longer periods. There are a number of factors which may prevent a Fund, or derivatives or other strategies used by a Fund, from achieving a desired correlation (or inverse correlation) with an index. These may include, but are not limited to: (i) the impact of fund fees, expenses and transaction costs, including borrowing and brokerage costs/ bid-ask spreads, which are not reflected in index returns; (ii) differences in the timing of daily calculations of the value of an index and the timing of the valuation of derivatives, securities and other assets held by a Fund and the determination of the NAV of Fund shares; (iii) disruptions or illiquidity in the markets for derivative instruments or securities in which a Fund invests; (iv) a Fund having exposure to or holding less than all of the securities in the underlying index and/or having exposure to or holding securities not included in the underlying index; (v) large or unexpected movements of assets into and out of a Fund (due to share purchases or redemptions, for example), potentially resulting in the Fund being over- or under-exposed to the index; (vi) the impact of accounting standards or changes thereto; (vii) changes to the applicable index that are not disseminated in advance; (viii) a possible need to conform a Fund's portfolio holdings to comply with investment restrictions or policies or regulatory or tax law requirements; and (ix) fluctuations in currency exchange rates.

Market and Other Risks. Like most other investments, derivative instruments are subject to the risk that the market value of the instrument will change in a way detrimental to a Fund's interest. If a portfolio manager incorrectly forecasts the values of securities, currencies or interest rates or other economic factors in using derivatives for a Fund, the Fund might have been in a better position if it had not entered into the transaction at all. While some strategies involving derivative instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other Fund investments. A Fund may also have to buy or sell a security at a disadvantageous time or price because the Fund is legally required to maintain offsetting positions or asset coverage in connection with certain derivatives transactions. The regulation of the derivatives markets has increased over the past several years, and additional future regulation of the derivatives markets may make derivatives more costly, may limit the availability or reduce the liquidity of derivatives, or may otherwise adversely affect the value or performance of derivatives. Any such adverse future developments could impair the effectiveness or raise the costs of a Fund's derivative transactions, or impede the employment of a Fund's derivatives strategies, or adversely affect a Fund's performance.

The PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund and PIMCO Enhanced Short Maturity Active Exchange-Traded Fund may also enter into, or acquire participations in, delayed funding loans and revolving credit facilities, in which a lender agrees to make loans up to a maximum amount upon demand by the borrower during a specified term. These commitments may have the effect of requiring the PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund and PIMCO Enhanced Short Maturity Active Exchange-Traded Fund to increase their respective investments in a company at a time when it might not otherwise decide to do so (including at a time when the company's financial condition makes it unlikely that such amounts will be repaid). To the extent that the PIMCO Active Bond Exchange-Traded Fund, PIMCO Enhanced Low Duration Active Exchange-Traded Fund and PIMCO Enhanced Short Maturity Active Exchange-Traded Fund are committed to advance additional funds, they will segregate or "earmark" assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees in an amount sufficient to meet such commitments. Delayed funding loans and revolving credit facilities are subject to credit, interest rate and liquidity risk and the risks of being a lender.

Each Fund may purchase or sell securities which it is eligible to purchase or sell on a when-issued basis, may purchase and sell such securities for delayed delivery and may make contracts to purchase or sell such securities for a fixed price at a future date beyond normal settlement time (forward commitments). When-issued transactions, delayed delivery purchases and forward commitments involve a risk of loss if the value of the securities declines prior to the settlement date. This risk is in addition to the risk that a Fund's other assets will decline in value. Therefore, these transactions may result in a form of leverage and increase a Fund's overall investment exposure. Typically, no income accrues on securities a Fund has committed to purchase prior to the time delivery of the securities is made, although the Fund may earn income on securities it has segregated or "earmarked" to cover these positions. When a Fund has sold a security on a when-issued, delayed delivery, or forward commitment basis, the Fund does not participate in future gains or losses with respect to the security. If the other party to a transaction fails to pay for the securities, a Fund could suffer a loss. Additionally, when selling a security on a when-issued, delayed delivery or forward commitment basis without owning the security, a Fund will incur a loss if the security's price appreciates in value such that the security's price is above the agreed-upon price on the settlement date.

Section 12(d)(1) of the 1940 Act restricts investments by registered investment companies and companies relying on Sections 3(c)(1) or 3(c)(7)

of the 1940 Act in the securities of other investment companies. Registered investment companies are permitted to invest in the Fund beyond the limits set forth in Section 12(d)(1), subject to certain terms and conditions set forth in an SEC exemptive order issued to PIMCO and the Trust, including that such investment companies enter into an agreement with the Trust.

Each Fund may invest in, to the extent permitted by Section 12(d)(1)(A) of the 1940 Act, other affiliated and unaffiliated funds, such as open-end or closed-end management investment companies, including other exchange traded funds, provided that the Fund's investment in units or shares of investment companies and other open-end collective investment vehicles will not exceed 10% of the Fund's total assets. Other unaffiliated investment companies are not required to make their shares available for purchase by a Fund, and there is no guarantee that such investment will be, or will continue to be, available. A Fund may invest securities lending collateral in one or more money market funds to the extent permitted by Rule 12d1-1 under the 1940 Act, including series of PIMCO Funds, an affiliated open-end management investment company managed by PIMCO. As a shareholder of a fund, the Fund may indirectly bear investment advisory fees, supervisory and administrative fees, service fees and other fees which are in addition to the fees the Fund pays its service providers.

Subject to the restrictions and limitations of the 1940 Act, each Fund may, in the future, elect to pursue its investment objective either by investing directly in securities, or by investing in one or more underlying investment vehicles or companies that have substantially similar investment objectives and policies as the Fund.

The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund may invest in equity securities of small-capitalization and mid-capitalization companies. The Funds consider a small-cap company to be a company with a market capitalization of up to $1.5 billion and a mid-cap company to be a company with a market capitalization of between $1.5 billion and $10 billion. Investments in small-cap and mid-cap companies involve greater risk than investments in large-capitalization companies. Small- and mid-cap companies may not have an established financial history, which can present valuation challenges. The equity securities of small- and mid-cap companies may be subject to increased market fluctuations, due to less liquid markets and more limited managerial and financial resources. A Fund's investment in small- and mid-cap companies may increase the volatility of the Fund's portfolio.

The PIMCO Active Bond Exchange-Traded Fund and PIMCO Enhanced Low Duration Active Exchange-Traded Fund may make short sales as part of its overall portfolio management strategies or to offset a potential decline in value of a security. A short sale involves the sale of a security that is borrowed from a broker or other institution to complete the sale. Short sales expose a Fund to the risk that it will be required to acquire, convert or exchange securities to replace the borrowed securities (also known as "covering" the short position) at a time when the securities sold short have appreciated in value, thus resulting in a loss to the Fund. When making a short sale (other than a "short sale against the box"), a Fund must segregate or "earmark" assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees or otherwise cover its position in a permissible manner. A Fund may engage in short selling to the extent permitted by the 1940 Act and rules and interpretations thereunder and other federal securities laws. To the extent a Fund engages in short selling in foreign (non-U.S.) jurisdictions, the Fund will do so to the extent permitted by the laws and regulations of such jurisdiction.

Each Fund may invest up to 15% of its net assets (taken at the time of investment) in illiquid securities. Certain illiquid securities may require pricing at fair value as determined in good faith under the supervision of the Board of Trustees. A portfolio manager may be subject to significant delays in disposing of illiquid securities, and transactions in illiquid securities may entail registration expenses and other transaction costs that are higher than those for transactions in liquid securities. The term "illiquid securities" for this purpose means securities that cannot be disposed of within seven days in the ordinary course of business at approximately the amount at which a Fund has valued the securities. Restricted securities, i.e., securities subject to legal or contractual restrictions on resale, may be illiquid. However, some restricted securities (such as securities issued pursuant to Rule 144A under the Securities Act of 1933, as amended, and certain commercial paper) may be treated as liquid, although they may be less liquid than registered securities traded on established secondary markets.

Although certain Funds may seek to maintain stable distributions, such Funds' distribution rates may be affected by numerous factors, including but not limited to changes in realized and projected market returns, fluctuations in market interest rates, Fund performance, and other factors. There can be no assurance that a change in market conditions or other factors will not result in a change in a Fund's distribution rate or that the rate will be sustainable in the future.

For instance, during periods of low or declining interest rates, a Fund's distributable income and dividend levels may decline for many reasons. For example, the Fund may have to deploy uninvested assets (whether from purchases of Fund shares, proceeds from matured, traded or called debt obligations or other sources) in new, lower yielding instruments. Additionally, payments from certain instruments that may be held by a Fund (such as variable and floating rate securities) may be negatively impacted by declining interest rates, which may also lead to a decline in the Fund's distributable income and dividend levels.

becomes insolvent. A Fund may pay lending fees to a party arranging the loan. Cash collateral received by a Fund in securities lending transactions may be invested in short-term liquid fixed income instruments or in money market or short-term mutual funds, or similar investment vehicles, including affiliated money market or short-term mutual funds. A Fund bears the risk of such investments.

The length of time a Fund has held a particular security is not generally a consideration in investment decisions. A change in the securities held by a Fund is known as "portfolio turnover." When a portfolio manager deems it appropriate and particularly during periods of volatile market movements, a Fund may engage in frequent and active trading of portfolio securities to achieve its investment objective. To the extent that Creation Unit purchases from and redemptions by a Fund are effected in cash, frequent purchases and redemptions may increase the rate of portfolio turnover. Higher portfolio turnover (e.g., an annual rate greater than 100% of the average value of a Fund's portfolio) involves correspondingly greater expenses to a Fund, including brokerage commissions or dealer markups and other transaction costs on the sale of securities and reinvestments in other securities. Such sales may also result in realization of taxable capital gains, including short-term capital gains (which are generally taxed at ordinary income tax rates). The trading costs and tax effects associated with portfolio turnover may adversely affect a Fund's performance. Please see a Fund's "Fund Summary—Portfolio Turnover" or the "Financial Highlights" in this prospectus for the portfolio turnover rates of the Funds that were operational during the last fiscal year. In addition, large movements of cash into or out of a Fund may negatively impact the Fund's ability to achieve its investment objective or maintain a consistent level of operating expenses.

For temporary defensive purposes, each Fund may invest without limit in U.S. debt securities, including taxable securities and short-term money market securities, when PIMCO deems it appropriate to do so. When a Fund engages in such strategies, it may not achieve its investment objective.

The investment objective of each Fund is non-fundamental and may be changed by the Board of Trustees without shareholder approval. Unless otherwise stated, all other investment policies of the Funds may be changed by the Board of Trustees without shareholder approval. In addition, the Trust may determine to cease operating any Fund as an "exchange-traded" fund and cause the Fund's shares to stop trading on a securities exchange.

Unless otherwise stated, all percentage limitations on Fund investments listed in this prospectus will apply at the time of investment. A Fund would not violate these limitations unless an excess or deficiency occurs or exists immediately after and as a result of an investment. Each of the PIMCO Active Bond Exchange-Traded Fund and PIMCO Government Limited Maturity Active Exchange-Traded Fund has adopted a non-fundamental investment policy, and each of the PIMCO Intermediate Municipal Bond Active Exchange-Traded and PIMCO Short Term Municipal Bond Active Exchange-Traded Funds has adopted a fundamental investment policy, to invest at least 80% of its assets in investments suggested by its name. For purposes of this policy, the term "assets" means net assets plus the amount of any borrowings for investment purposes.

Rating agencies are private services that provide ratings of the credit quality of fixed income securities, including convertible securities. Appendix A to this prospectus describes the various ratings assigned to fixed income securities by Moody's, S&P and Fitch. Ratings assigned by a rating agency are not absolute standards of credit quality and do not evaluate market risks. Rating agencies may fail to make timely changes in credit ratings and an issuer's current financial condition may be better or worse than a rating indicates. A Fund will not necessarily sell a security when its rating is reduced below its rating at the time of purchase. PIMCO does not rely solely on credit ratings, and develops its own analysis of issuer credit quality.

A Fund may purchase unrated securities (which are not rated by a rating agency) if PIMCO determines, in its sole discretion, that the security is of comparable quality to a rated security that the Fund may purchase. In making ratings determinations, PIMCO may take into account different factors than those taken into account by rating agencies, and PIMCO's rating of a security may differ from the rating that a rating agency may have given the same security. Unrated securities may be less liquid than comparable rated securities and involve the risk that the portfolio manager may not accurately evaluate the security's comparative credit rating. Analysis of the creditworthiness of issuers of high yield securities may be more complex than for issuers of higher-quality fixed income securities. To the extent that a Fund invests in high yield and/or unrated securities, the Fund's success in achieving its investment objective may depend more heavily on the portfolio manager's creditworthiness analysis than if the Fund invested exclusively in higher-quality and rated securities.

The Funds may invest in other types of securities and use a variety of investment techniques and strategies which are not described in this prospectus. These securities and techniques may subject the Funds to additional risks. Please see the SAI for additional information about the securities and investment techniques described in this prospectus and about additional securities and techniques that may be used by the Funds.

party service providers (including but not limited to advisers, sub-advisers, administrators, transfer agents, custodians, distributors and other third parties), trading counterparties or issuers in which a Fund invests can also subject a Fund to many of the same risks associated with direct cyber security breaches. Moreover, cyber security breaches involving trading counterparties or issuers in which a Fund invests could adversely impact such counterparties or issuers and cause the Fund's investment to lose value.

Cyber security failures or breaches may result in financial losses to a Fund and its shareholders. These failures or breaches may also result in disruptions to business operations, potentially resulting in financial losses; interference with a Fund's ability to calculate its NAV, process shareholder transactions or otherwise transact business with shareholders; impediments to trading; violations of applicable privacy and other laws; regulatory fines; penalties; reputational damage; reimbursement or other compensation costs; additional compliance and cyber security risk management costs and other adverse consequences. In addition, substantial costs may be incurred in order to prevent any cyber incidents in the future.

Like with operational risk in general, the Funds have established business continuity plans and risk management systems designed to reduce the risks associated with cyber security. However, there are inherent limitations in these plans and systems, including that certain risks may not have been identified, in large part because different or unknown threats may emerge in the future. As such, there is no guarantee that such efforts will succeed, especially because the Funds do not directly control the cyber security systems of issuers in which a Fund may invest, trading counterparties or third party service providers to the Funds. There is also a risk that cyber security breaches may not be detected. The Funds and their shareholders could be negatively impacted as a result.

The financial highlights table is intended to help a shareholder understand each Fund's financial performance for the last five fiscal years or, if shorter, the period since a Fund commenced operations. Certain information reflects financial results for a single Fund share. Because the PIMCO Government Limited Maturity Active Exchange-Traded Fund and PIMCO Prime Limited Maturity Active Exchange-Traded Fund had not commenced operations during the periods shown, financial performance information is not provided for these Funds. The total returns in the table represent the rate that an investor would have earned or lost on an investment in shares of a Fund (assuming reinvestment of all dividends and distributions). This information has been audited by PricewaterhouseCoopers LLP, whose report, along with each Fund's financial statements, are included in the Trust's annual report to shareholders. The annual report is available free of charge by calling the Trust at the phone number on the back of this prospectus. The annual report is also available for download free of charge on the Trust's web site at www.pimcoetfs.com. Note: All footnotes to the financial highlights table appear at the end of the tables.

The Fund's investments may range in quality from securities rated in the lowest category in which the Fund is permitted to invest to securities rated in the highest category (as rated by Moody's, Standard & Poor's or Fitch, or, if unrated, determined by PIMCO to be of comparable quality). The percentage of the Fund's assets invested in securities in a particular rating category will vary. The following terms are generally used to describe the credit quality of fixed income securities:

High Quality Debt Securities are those rated in one of the two highest rating categories (the highest category for commercial paper) or, if unrated, deemed comparable by PIMCO.

Investment Grade Debt Securities are those rated in one of the four highest rating categories, or if unrated deemed comparable by PIMCO.

Below Investment Grade High Yield Securities ("Junk Bonds"), are those rated lower than Baa by Moody's, BBB by Standard & Poor's or Fitch, and comparable securities. They are deemed predominantly speculative with respect to the issuer's ability to repay principal and interest.

The following is a description of Moody's, Standard & Poor's and Fitch's rating categories applicable to fixed income securities.

Ratings assigned on Moody's global long-term rating scales are forward-looking opinions of the relative credit risks of financial obligations issued by non-financial corporations, financial institutions, structured finance vehicles, project finance vehicles, and public sector entities. Long-term ratings are assigned to issuers or obligations with an original maturity of one year or more and reflect both on the likelihood of a default on contractually promised payments and the expected financial loss suffered in the event of default.

Aaa: Obligations rated Aaa are judged to be of the highest quality, subject to the lowest level of credit risk.

Aa: Obligations rated Aa are judged to be of high quality and are subject to very low credit risk.

A: Obligations rated A are judged to be upper-medium grade and are subject to low credit risk.

Baa: Obligations rated Baa are judged to be medium-grade and subject to moderate credit risk and as such may possess certain speculative characteristics.

Ba: Obligations rated Ba are judged to be speculative and are subject to substantial credit risk.

B: Obligations rated B are considered speculative and are subject to high credit risk.

Caa: Obligations rated Caa are judged to be speculative of poor standing and are subject to very high credit risk.

Ca: Obligations rated Ca are highly speculative and are likely in, or very near, default, with some prospect of recovery of principal and interest.

C: Obligations rated C are the lowest rated and are typically in default, with little prospect for recovery of principal or interest.

Moody's appends numerical modifiers 1, 2, and 3 to each generic rating classification from Aa through Caa. The modifier 1 indicates that the obligation ranks in the higher end of its generic rating category; the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates a ranking in the lower end of that generic rating category. Additionally, a "(hyb)" indicator is appended to all ratings of hybrid securities issued by banks, insurers, finance companies, and securities firms.*

* By their terms, hybrid securities allow for the omission of scheduled dividends, interest, or principal payments, which can potentially result in impairment if such an omission occurs. Hybrid securities may also be subject to contractually allowable write-downs of principal that could result in impairment. Together with the hybrid indicator, the long-term obligation rating assigned to a hybrid security is an expression of the relative credit risk associated with that security.

Moody's assigns provisional ratings to medium-term note (MTN) programs and definitive ratings to the individual debt securities issued from them (referred to as drawdowns or notes).

MTN program ratings are intended to reflect the ratings likely to be assigned to drawdowns issued from the program with the specified priority of claim (e.g., senior or subordinated). To capture the contingent nature of a program rating, Moody's assigns provisional ratings to MTN programs. A provisional rating is denoted by a (P) in front of the rating.

The rating assigned to a drawdown from a rated MTN or bank/deposit note program is definitive in nature, and may differ from the program rating if the drawdown is exposed to additional credit risks besides the issuer's default, such as links to the defaults of other issuers, or has other structural features that warrant a different rating. In some circumstances, no rating may be assigned to a drawdown.

Moody's encourages market participants to contact Moody's Ratings Desks or visit www.moodys.com directly if they have questions regarding ratings for specific notes issued under a medium-term note program. Unrated notes issued under an MTN program may be assigned an NR (not rated) symbol.

Global Short-Term Rating Scale
Ratings assigned on Moody's global short-term rating scales are forward-looking opinions of the relative credit risks of financial obligations issued by non-financial corporates, financial institutions, structured finance vehicles, project finance vehicles, and public sector entities. Short-term ratings are assigned to obligations with an original maturity of thirteen months or less and reflect both on the likelihood of a default on contractually promised payments and the expected financial loss suffered in the event of default.

Moody's employs the following designations to indicate the relative repayment ability of rated issuers:

P-1: Issuers (or supporting institutions) rated Prime-1 have a superior ability to repay short-term debt obligations.

P-2: Issuers (or supporting institutions) rated Prime-2 have a strong ability to repay short-term debt obligations.

P-3: Issuers (or supporting institutions) rated Prime-3 have an acceptable ability to repay short-term obligations.

NP: Issuers (or supporting institutions) rated Not Prime do not fall within any of the Prime rating categories.

Moody's long-term National Scale Ratings (NSRs) are opinions of the relative creditworthiness of issuers and financial obligations within a particular country. NSRs are not designed to be compared among countries; rather, they address relative credit risk within a given country. Moody's assigns national scale ratings in certain local capital markets in which investors have found the global rating scale provides inadequate differentiation among credits or is inconsistent with a rating scale already in common use in the country. In each specific country, the last two characters of the rating indicate the country in which the issuer is located (e.g., Aaa.br for Brazil).

Aaa.n: Issuers or issues rated Aaa.n demonstrate the strongest creditworthiness relative to other domestic issuers.

Aa.n: Issuers or issues rated Aa.n demonstrate very strong creditworthiness relative to other domestic issuers.

A.n: Issuers or issues rated A.n present above-average creditworthiness relative to other domestic issuers.

Baa.n: Issuers or issues rated Baa.n represent average creditworthiness relative to other domestic issuers.

Ba.n: Issuers or issues rated Ba.n demonstrate below-average creditworthiness relative to other domestic issuers.

B.n: Issuers or issues rated B.n demonstrate weak creditworthiness relative to other domestic issuers.

Caa.n: Issuers or issues rated Caa.n demonstrate very weak creditworthiness relative to other domestic issuers.

Ca.n: Issuers or issues rated Ca.n demonstrate extremely weak creditworthiness relative to other domestic issuers.

C.n: Issuers or issues rated C.n demonstrate the weakest creditworthiness relative to other domestic issuers.

Moody's appends numerical modifiers 1, 2, and 3 to each generic rating classification from Aa through Caa. The modifier 1 indicates that the obligation ranks in the higher end of its generic rating category; the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates a ranking in the lower end of that generic rating category. National scale long-term ratings of D.ar and E.ar may also be applied to Argentine obligations.

National Scale Short-Term Ratings
Moody's short-term NSRs are opinions of the ability of issuers in a given country, relative to other domestic issuers, to repay debt obligations that have an original maturity not exceeding thirteen months. Short-term NSRs in one country should not be compared with short-term NSRs in another country, or with Moody's global ratings.

There are four categories of short-term national scale ratings, generically denoted N-1 through N-4 as defined below.

In each specific country, the first two letters indicate the country in which the issuer is located (e.g., BR-1 through BR-4 for Brazil).

N-1: Issuers rated N-1 have the strongest ability to repay short-term senior unsecured debt obligations relative to other domestic issuers.

N-2: Issuers rated N-2 have an above average ability to repay short-term senior unsecured debt obligations relative to other domestic issuers.

N-3: Issuers rated N-3 have an average ability to repay short-term senior unsecured debt obligations relative to other domestic issuers.

N-4: Issuers rated N-4 have a below average ability to repay short-term senior unsecured debt obligations relative to other domestic issuers.

The short-term rating symbols P-1.za, P-2.za, P-3.za and NP.za are used in South Africa. National scale short-term ratings of AR-5 and AR-6 may also be applied to Argentine obligations.

Short-Term Obligation Ratings
The Municipal Investment Grade (MIG) scale is used to rate US municipal bond anticipation notes of up to three years maturity. Municipal notes rated on the MIG scale may be secured by either pledged revenues or proceeds of a take-out financing received prior to note maturity. MIG ratings expire at the maturity of the obligation, and the issuer's long-term rating is only one consideration in assigning the MIG rating. MIG ratings are divided into three levels--MIG 1 through MIG 3--while speculative grade short-term obligations are designated SG.

MIG 1: This designation denotes superior credit quality. Excellent protection is afforded by established cash flows, highly reliable liquidity support, or demonstrated broad-based access to the market for refinancing.

MIG 2: This designation denotes strong credit quality. Margins of protection are ample, although not as large as in the preceding group.

MIG 3: This designation denotes acceptable credit quality. Liquidity and cash-flow protection may be narrow, and market access for refinancing is likely to be less well-established.

SG: This designation denotes speculative-grade credit quality. Debt instruments in this category may lack sufficient margins of protection.

Demand Obligation Ratings
In the case of variable rate demand obligations (VRDOs), a two-component rating is assigned: a long- or short-term debt rating and a demand obligation rating. The first element represents Moody's evaluation of risk associated with scheduled principal and interest payments. The second element represents Moody's evaluation of risk associated with the ability to receive purchase price upon demand ("demand feature"). The second element uses a rating from a variation of the MIG scale called the Variable Municipal Investment Grade (VMIG) scale.

VMIG 1: This designation denotes superior credit quality. Excellent protection is afforded by the superior short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.

VMIG 2: This designation denotes strong credit quality. Good protection is afforded by the strong short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.

VMIG 3: This designation denotes acceptable credit quality. Adequate protection is afforded by the satisfactory short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.

SG: This designation denotes speculative-grade credit quality. Demand features rated in this category may be supported by a liquidity provider that does not have an investment grade short-term rating or may lack the structural and/or legal protections necessary to ensure the timely payment of purchase price upon demand.

Long-Term Issue Credit Ratings
Issue credit ratings are based, in varying degrees, on S&P Global Ratings' ("S&P") analysis of the following considerations:

Likelihood of payment—capacity and willingness of the obligor to meet its financial commitment on a financial obligation in accordance with the terms of the obligation;

Protection afforded by, and relative position of, the financial obligation in the event of a bankruptcy, reorganization, or other arrangement under the laws of bankruptcy and other laws affecting creditors' rights.

Issue ratings are an assessment of default risk, but may incorporate an assessment of relative seniority or ultimate recovery in the event of default. Junior obligations are typically rated lower than senior obligations, to reflect the lower priority in bankruptcy, as noted above. (Such differentiation may apply when an entity has both senior and subordinated obligations, secured and unsecured obligations, or operating company and holding company obligations.)

Investment Grade
AAA: An obligation rated 'AAA' has the highest rating assigned by S&P. The obligor's capacity to meet its financial commitment on the obligation is extremely strong.

AA: An obligation rated 'AA' differs from the highest-rated obligations only to a small degree. The obligor's capacity to meet its financial commitment on the obligation is very strong.

A: An obligation rated 'A' is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher-rated categories. However, the obligor's capacity to meet its financial commitment on the obligation is still strong.

BBB: An obligation rated ‘BBB' exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity of the obligor to meet its financial commitment on the obligation.

Speculative Grade
Obligations rated 'BB', 'B', 'CCC', 'CC', and 'C' are regarded as having significant speculative characteristics. 'BB' indicates the least degree of speculation and 'C' the highest. While such obligations will likely have some quality and protective characteristics, these may be outweighed by large uncertainties or major exposures to adverse conditions.

BB: An obligation rated 'BB' is less vulnerable to nonpayment than other speculative issues. However, it faces major ongoing uncertainties or exposure to adverse business, financial, or economic conditions which could lead to the obligor's inadequate capacity to meet its financial commitment on the obligation.

B: An obligation rated 'B' is more vulnerable to nonpayment than obligations rated ‘BB', but the obligor currently has the capacity to meet its financial commitment on the obligation. Adverse business, financial, or economic conditions will likely impair the obligor's capacity or willingness to meet its financial commitment on the obligation.

CCC: An obligation rated 'CCC' is currently vulnerable to nonpayment, and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitment on the obligation. In the event of adverse business, financial, or economic conditions, the obligor is not likely to have the capacity to meet its financial commitment on the obligation.

CC: An obligation rated 'CC' is currently highly vulnerable to nonpayment. The ‘CC' rating is used when a default has not yet occurred, but S&P expects default to be a virtual certainty, regardless of the anticipated time to default.

C: An obligation rated ‘C' is currently highly vulnerable to nonpayment, and the obligation is expected to have lower relative seniority or lower ultimate recovery compared to obligations that are rated higher.

D: An obligation rated ‘D' is in default or in breach of an imputed promise. For non-hybrid capital instruments, the ‘D' rating category is used when payments on an obligation are not made on the date due, unless S&P believes that such payments will be made within five business days in the absence of a stated grace period or within the earlier of the stated grace period or 30 calendar days. The ‘D' rating also will be used upon the filing of a bankruptcy petition or the taking of similar action and where default on an obligation is a virtual certainty, for example due to automatic stay provisions. An obligation's rating is lowered to ‘D' if it is subject to a distressed exchange offer.

NR: This indicates that a rating has not been assigned or is no longer assigned.

Plus (+) or minus (-): The ratings from ‘AA' to 'CCC' may be modified by the addition of a plus (+) or minus (-) sign to show relative standing within the major rating categories.

Short-Term Issue Credit Ratings
A-1: A short-term obligation rated 'A-1' is rated in the highest category by S&P. The obligor's capacity to meet its financial commitment on the obligation is strong. Within this category, certain obligations are designated with a plus sign (+). This indicates that the obligor's capacity to meet its financial commitment on these obligations is extremely strong.

A-2: A short-term obligation rated 'A-2' is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher rating categories. However, the obligor's capacity to meet its financial commitment on the obligation is satisfactory.

A-3: A short-term obligation rated 'A-3' exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity of the obligor to meet its financial commitment on the obligation.

B: A short-term obligation rated 'B' is regarded as vulnerable and has significant speculative characteristics. The obligor currently has the capacity to meet its financial commitments; however, it faces major ongoing uncertainties which could lead to the obligor's inadequate capacity to meet its financial commitments.

C: A short-term obligation rated 'C' is currently vulnerable to nonpayment and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitment on the obligation.

D: A short-term obligation rated ‘D' is in default or in breach of an imputed promise. For non-hybrid capital instruments, the ‘D' rating category is used when payments on an obligation are not made on the date due, unless S&P believes that such payments will be made within any stated grace period. However, any stated grace period longer than five business days will be treated as five business days. The ‘D' rating also will be used upon the filing of a bankruptcy petition or the taking of a similar action and where default on an obligation is a virtual certainty, for example due to automatic stay provisions. An obligation's rating is lowered to ‘D' if it is subject to a distressed exchange offer.

Dual Ratings: Dual ratings may be assigned to debt issues that have a put option or demand feature. The first component of the rating addresses the likelihood of repayment of principal and interest as due, and the second component of the rating addresses only the demand feature. The first component of the rating can relate to either a short-term or long-term transaction and accordingly use either short-term or long-term rating symbols. The second component of the rating relates to the put option and is assigned a short-term rating symbol (for example, ‘AAA/A-1+' or ‘A-1+/A-1'). With U.S. municipal short-term demand debt, the U.S. municipal short-term note rating symbols are used for the first component of the rating (for example, ‘SP-1+/A-1+').

Active Qualifiers
S&P uses the following qualifiers that limit the scope of a rating. The structure of the transaction can require the use of a qualifier such as a 'p' qualifier, which indicates the rating addressed the principal portion of the obligation only. A qualifier appears as a suffix and is part of the rating.

L: Ratings qualified with ‘L' apply only to amounts invested up to federal deposit insurance limits.

p: This suffix is used for issues in which the credit factors, the terms, or both, that determine the likelihood of receipt of payment of principal are different from the credit factors, terms or both that determine the likelihood of receipt of interest on the obligation. The ‘p' suffix indicates that the rating addresses the principal portion of the obligation only and that the interest is not rated.

prelim: Preliminary ratings, with the 'prelim' suffix, may be assigned to obligors or obligations, including financial programs, in the circumstances described below. Assignment of a final rating is conditional on the receipt by S&P of appropriate documentation. S&P reserves the right not to issue a final rating. Moreover, if a final rating is issued, it may differ from the preliminary rating.

Preliminary ratings may be assigned to obligations, most commonly structured and project finance issues, pending receipt of final documentation and legal opinions.

Preliminary ratings may be assigned to obligations that will likely be issued upon the obligor's emergence from bankruptcy or similar reorganization, based on late-stage reorganization plans, documentation and discussions with the obligor. Preliminary ratings may also be assigned to the obligors. These ratings consider the anticipated general credit quality of the reorganized or post-bankruptcy issuer as well as attributes of the anticipated obligation(s).

Preliminary ratings may be assigned to entities that are being formed or that are in the process of being independently established when, in S&P opinion, documentation is close to final. Preliminary ratings may also be assigned to the obligations of these entities.

Preliminary ratings may be assigned when a previously unrated entity is undergoing a well-formulated restructuring, recapitalization, significant financing or other transformative event, generally at the point that investor or lender commitments are invited. The preliminary rating may be assigned to the entity and to its proposed obligation(s). These preliminary ratings consider the anticipated general credit quality of the obligor, as well as attributes of the anticipated obligation(s), assuming successful completion of the transformative event. Should the transformative event not occur, S&P would likely withdraw these preliminary ratings.

A preliminary recovery rating may be assigned to an obligation that has a preliminary issue credit rating.

t: This symbol indicates termination structures that are designed to honor their contracts to full maturity or, should certain events occur, to terminate and cash settle all their contracts before their final maturity date.

cir: This symbol indicates a Counterparty Instrument Rating (CIR), which is a forward-looking opinion about the creditworthiness of an issuer in a securitization structure with respect to a specific financial obligation to a counterparty (including interest rate swaps, currency swaps, and liquidity facilities). The CIR is determined on an ultimate payment basis; these opinions do not take into account timeliness of payment.

*:This symbol that indicated that the rating was contingent upon S&P receipt of an executed copy of the escrow agreement or closing documentation confirming investments and cash flows. Discontinued use in August 1998.

c: This qualifier was used to provide additional information to investors that the bank may terminate its obligation to purchase tendered bonds if the long-term credit rating of the issuer was lowered to below an investment-grade level and/or the issuer's bonds were deemed taxable. Discontinued use in January 2001.

G: The letter 'G' followed the rating symbol when a fund's portfolio consisted primarily of direct U.S. government securities.

pi: This qualifier was used to indicate ratings that were based on an analysis of an issuer's published financial information, as well as additional information in the public domain. Such ratings did not, however, reflect in-depth meetings with an issuer's management and therefore, could have been based on less comprehensive information than ratings without a 'pi' suffix. Discontinued use as of December 2014 and as of August 2015 for Lloyd's Syndicate Assessments.

pr: The letters ‘pr' indicate that the rating was provisional. A provisional rating assumed the successful completion of a project financed by the debt being rated and indicates that payment of debt service requirements was largely or entirely dependent upon the successful, timely completion of the project. This rating, however, while addressing credit quality subsequent to completion of the project, made no comment on the likelihood of or the risk of default upon failure of such completion.

q: A ‘q' subscript indicates that the rating is based solely on quantitative analysis of publicly available information. Discontinued use in April 2001.

r: The ‘r' modifier was assigned to securities containing extraordinary risks, particularly market risks, which are not covered in the credit rating. The absence of an ‘r' modifier should not be taken as an indication that an obligation would not exhibit extraordinary non-credit related risks. S&P discontinued the use of the ‘r' modifier for most obligations in June 2000 and for the balance of obligations (mainly structured finance transactions) in November 2002.

Long-Term Credit Ratings
Investment Grade
Rated entities in a number of sectors, including financial and non-financial corporations, sovereigns, insurance companies and certain sectors within public finance, are generally assigned Issuer Default Ratings (IDRs). IDRs are also assigned to certain entities in global infrastructure, project finance, and public finance. IDRs opine on an entity's relative vulnerability to default (including by way of a distressed debt exchange) on financial obligations. The threshold default risk addressed by the IDR is generally that of the financial obligations whose non-payment would best reflect the uncured failure of that entity. As such, IDRs also address relative vulnerability to bankruptcy, administrative receivership or similar concepts.

In aggregate, IDRs provide an ordinal ranking of issuers based on the agency's view of their relative vulnerability to default, rather than a prediction of a specific percentage likelihood of default.

AAA: Highest credit quality. ‘AAA' ratings denote the lowest expectation of credit risk. They are assigned only in cases of exceptionally strong capacity for payment of financial commitments. This capacity is highly unlikely to be adversely affected by foreseeable events.

AA: Very high credit quality. 'AA' ratings denote expectations of very low credit risk. They indicate very strong capacity for payment of financial commitments. This capacity is not significantly vulnerable to foreseeable events.

A: High credit quality. 'A' ratings denote expectations of low credit risk. The capacity for payment of financial commitments is considered strong. This capacity may, nevertheless, be more vulnerable to adverse business or economic conditions than is the case for higher ratings.

BBB: Good credit quality. 'BBB' ratings indicate that expectations of credit risk are currently low. The capacity for payment of financial commitments is considered adequate, but adverse business or economic conditions are more likely to impair this capacity.

Speculative Grade
BB: Speculative. ‘BB' ratings indicate an elevated vulnerability to credit risk, particularly in the event of adverse changes in business or economic conditions over time; however, business or financial alternatives may be available to allow financial commitments to be met.

B: Highly speculative. ‘B' ratings indicate that material credit risk is present.

Defaulted obligations typically are not assigned 'RD' or ‘D' ratings, but are instead rated in the ‘B' to ‘C' rating categories, depending on their recovery prospects and other relevant characteristics. This approach better aligns obligations that have comparable overall expected loss but varying vulnerability to default and loss.

The modifiers "+" or "-" may be appended to a rating to denote relative status within major rating categories. For example, the rating category 'AA' has three notch-specific rating levels ('AA+'; 'AA'; 'AA-'; each a rating level). Such suffixes are not added to the ‘AAA' obligation rating category, or to corporate finance obligation ratings in the categories below ‘CCC.'

The subscript ‘emr' is appended to a rating to denote embedded market risk that is beyond the scope of the rating. The designation is intended to make clear that the rating solely addresses the counterparty risk of the issuing bank. It is not meant to indicate any limitation in the analysis of the counterparty risk, which in all other respects follows published Fitch criteria for analyzing the issuing financial institution. Fitch does not rate these instruments where the principal is to any degree subject to market risk.

Recovery Ratings
Recovery Ratings are assigned to selected individual securities and obligations, most frequently for individual obligations of corporate finance issuers with Issuer Default Ratings (IDRs) in speculative grade categories.

Among the factors that affect recovery rates for securities are the collateral, the seniority relative to other obligations in the capital structure (where appropriate), and the expected value of the company or underlying collateral in distress.

The Recovery Rating scale is based on the expected relative recovery characteristics of an obligation upon the curing of a default, emergence from insolvency or following the liquidation or termination of the obligor or its associated collateral.

Recovery Ratings are an ordinal scale and do not attempt to precisely predict a given level of recovery. As a guideline in developing the rating assessments, the agency employs broad theoretical recovery bands in its ratings approach based on historical averages and analytical judgment, but

actual recoveries for a given security may deviate materially from historical averages.

RR1: Outstanding recovery prospects given default. ‘RR1' rated securities have characteristics consistent with securities historically recovering 91%-100% of current principal and related interest.

RR2: Superior recovery prospects given default. ‘RR2' rated securities have characteristics consistent with securities historically recovering 71%-90% of current principal and related interest.

RR3: Good recovery prospects given default. ‘RR3' rated securities have characteristics consistent with securities historically recovering 51%-70% of current principal and related interest.

RR4: Average recovery prospects given default. ‘RR4' rated securities have characteristics consistent with securities historically recovering 31%-50% of current principal and related interest.

RR5: Below average recovery prospects given default. ‘RR5' rated securities have characteristics consistent with securities historically recovering 11%-30% of current principal and related interest.

RR6: Poor recovery prospects given default. ‘RR6' rated securities have characteristics consistent with securities historically recovering 0%-10% of current principal and related interest.

Short-Term Credit Ratings
A short-term issuer or obligation rating is based in all cases on the short-term vulnerability to default of the rated entity and relates to the capacity to meet financial obligations in accordance with the documentation governing the relevant obligation. Short-term deposit ratings may be adjusted for loss severity. Short-Term Ratings are assigned to obligations whose initial maturity is viewed as "short term" based on market convention. Typically, this means up to 13 months for corporate, sovereign, and structured obligations, and up to 36 months for obligations in U.S. public finance markets.

F1: Highest short-term credit quality. Indicates the strongest intrinsic capacity for timely payment of financial commitments; may have an added "+" to denote any exceptionally strong credit feature.

F2: Good short-term credit quality. Good intrinsic capacity for timely payment of financial commitments.

F3: Fair short-term credit quality. The intrinsic capacity for timely payment of financial commitments is adequate.

B: Speculative short-term credit quality. Minimal capacity for timely payment of financial commitments, plus heightened vulnerability to near term adverse changes in financial and economic conditions.

RD: Restricted default. Indicates an entity that has defaulted on one or more of its financial commitments, although it continues to meet other financial obligations. Typically applicable to entity ratings only.

D: Default. Indicates a broad-based default event for an entity, or the default of a short-term obligation.

State Street Bank & Trust Co., State Street Financial Center, One Lincoln Street, Boston, MA 02111

PricewaterhouseCoopers LLP, 1100 Walnut Street, Suite 1300, Kansas City, MO 64106-2197

For further information about the PIMCO ETF Trust, call 888.400.ETF or visit our website at www.pimcoetfs.com.

The Trust's SAI and annual and semi-annual reports to shareholders include additional information about the Funds. The SAI and the financial statements included in the Funds' most recent annual report to shareholders are incorporated by reference into this prospectus, which means they are part of this prospectus for legal purposes. The Funds' annual report discusses the market conditions and investment strategies that significantly affected each Fund's performance during its last fiscal year.

You may get free copies of any of these materials or request other information about a Fund by calling the Trust at 888.400.4ETF (888.400.4383), by visiting www.pimcoetfs.com or by writing to:

You may review and copy information about the Trust, including its SAI, at the Securities and Exchange Commission's public reference room in Washington, D.C. You may call the Commission at 1-202-551-8090 for information about the operation of the public reference room. You may also access reports and other information about the Trust on the EDGAR Database on the Commission's web site at www.sec.gov. You may get copies of this information, with payment of a duplication fee, by writing the Public Reference Section of the Commission, 100 F Street N.E., Washington, D.C. 20549-1520, or by e-mailing your request to publicinfo@sec.gov.

You can also visit our web site at www.pimcoetfs.com for additional information about the Funds, including the SAI and the annual and semi-annual reports, which are available for download free of charge.

Reference the Trust's Investment Company Act file number in your correspondence.

PIMCO ETFs

Prospectus

October 31, 2018

Index Exchange-Traded Funds

	TICKER	EXCHANGE
TREASURY
PIMCO 1-3 Year U.S. Treasury Index Exchange-Traded Fund	TUZ	NYSE Arca
PIMCO 25+ Year Zero Coupon U.S. Treasury Index Exchange-Traded Fund	ZROZ	NYSE Arca
TREASURY INFLATION PROTECTED SECURITIES (TIPS)
PIMCO 1-5 Year U.S. TIPS Index Exchange-Traded Fund	STPZ	NYSE Arca
PIMCO 15+ Year U.S. TIPS Index Exchange-Traded Fund	LTPZ	NYSE Arca
PIMCO Broad U.S. TIPS Index Exchange-Traded Fund	TIPZ	NYSE Arca
CORPORATE
PIMCO 0-5 Year High Yield Corporate Bond Index Exchange-Traded Fund	HYS	NYSE Arca
PIMCO Investment Grade Corporate Bond Index Exchange-Traded Fund	CORP	NYSE Arca

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of The ICE BofAML 1-3 Year US Treasury Index.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities ("Component Securities") of The ICE BofAML 1-3 Year US Treasury Index (the "Underlying Index"). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which Pacific Investment Management Company LLC ("PIMCO") believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The average portfolio duration of this Fund will closely correspond to the portfolio duration of the securities comprising its Underlying Index, as calculated by PIMCO, which as of September 30, 2018 was 1.87 years. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates.

The Underlying Index is an unmanaged index comprised of U.S. dollar denominated sovereign debt securities publicly issued by the U.S. Treasury having a maturity of at least 1 year and less than 3 years. As of September 30, 2018, there were 98 issues in the Underlying Index. The securities in the Underlying Index have a minimum $1 billion of outstanding face value, have one to three years remaining to maturity, are fixed-rate and are non-convertible. Bills, inflation-indexed debt and strips are excluded from the Underlying Index; however, original issue zero coupon bonds are included in the Underlying Index and the amounts outstanding of qualifying coupon securities are not reduced by any portions that have been stripped. The Underlying Index is capitalization-weighted and the composition of Component Securities is updated monthly. It is not possible to invest directly in the Underlying Index. Intra-month cash flows are reinvested daily, at the beginning-of-month 1-month LIBID rate, until the end of the month at which point all cash is removed from the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes.

PIMCO uses an indexing approach in managing the Fund's investments. The Fund employs a representative sampling strategy in seeking to achieve its investment objective. In using this strategy, PIMCO seeks to invest in a combination of Component Securities and other instruments, or in Component Securities but in different proportions as compared to the weighting of the Underlying Index, such that the portfolio effectively provides exposure to the Underlying Index. In using a representative sampling strategy, the Fund may not track its Underlying Index with the same degree of accuracy as a fund that replicates the composition and weighting of the Underlying Index. Unlike many investment companies, the Fund does not attempt to outperform the index the Fund tracks. An indexing approach may eliminate the chance that the Fund will substantially outperform its Underlying Index but also may reduce some of the risks of active management. Indexing seeks to achieve lower costs by keeping portfolio turnover low in comparison to actively managed investment companies.

The Fund may invest in derivative instruments, such as options, futures contracts or swap agreements. The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs). The "total return" sought by the Fund consists of income earned on the Fund's investments, plus capital appreciation, if any, which generally arises from decreases in interest rates.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund's use of derivatives may result in losses to the Fund, a reduction in the Fund's returns and/or increased volatility. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction. Changes in regulation relating to a fund's use of derivatives and related instruments could potentially limit or impact the Fund's ability to invest in derivatives, limit the Fund's ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund's performance

Management and Tracking Error Risk: the risk that the portfolio manager's investment decisions may not produce the desired results or that the Fund's portfolio may not closely track the Underlying Index for a number of reasons. The Fund incurs operating expenses, which are not applicable to the Underlying Index, and the costs of buying and selling securities, especially when rebalancing the Fund's portfolio to reflect changes in the composition of the Underlying Index. Performance of the Fund and the Underlying Index may vary due to asset valuation differences and differences between the Fund's portfolio and the Underlying Index due to legal restrictions, cost or liquidity restraints. The risk that performance of the Fund and the Underlying Index may vary may be heightened during periods of increased market volatility or other unusual market conditions. In addition, the Fund's use of a representative sampling approach may cause the Fund to be less correlated to the return of the Underlying Index than if the Fund held all of the securities in the Underlying Index

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

The ICE BofAML 1-3 Year US Treasury Index is an unmanaged index comprised of U.S. Treasury securities, other than inflation-protection securities and Separate Trading of Registered Interest and Principal of Securities, with at least $1 billion in outstanding face value and a remaining term to final maturity of at least one year and less than three years. Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is 0.18%. For the periods shown in the bar chart, the highest quarterly return was 1.13% in the Q2 2010, and the lowest quarterly return was -0.47% in the Q4 2016.

PIMCO serves as the investment adviser for the Fund. The Fund's portfolio is jointly and primarily managed by Matthew P. Dorsten, Mitchell Handa and Graham A. Rennison. Mr. Dorsten is an Executive Vice President of PIMCO, Mr. Rennison is a Senior Vice President of PIMCO and Mr. Handa is a Vice President of PIMCO. Mr. Dorsten has jointly and primarily managed the Fund since December 2015. Each of Messrs. Handa and Rennison has jointly and primarily managed the Fund since October 2018.

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of The ICE BofAML Long US Treasury Principal STRIPS Index.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities ("Component Securities") of The ICE BofAML Long US Treasury Principal STRIPS Index (the "Underlying Index"). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which Pacific Investment Management Company LLC ("PIMCO") believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The average portfolio duration of this Fund will closely correspond to the portfolio duration of the securities comprising its Underlying Index, as calculated by PIMCO, which as of September 30, 2018 was 27.42 years. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates.

The Underlying Index is an unmanaged index comprised of long maturity Separate Trading of Registered Interest and Principal of Securities ("STRIPS") representing the final principal payment of U.S. Treasury bonds. The principal STRIPS comprising the Underlying Index must have 25 years or more remaining term to final maturity and must be stripped from U.S. Treasury bonds having at least $1 billion in outstanding face value. As of September 30, 2018 there were 20 issues in the Underlying Index. Index constituents are capitalization-weighted based on the security prices times an assumed face value of $1 billion per constituent security. The Underlying Index is rebalanced quarterly on March 31, June 30, September 30 and December 31, based on information available up to and including the third business day before the last business day of the rebalancing month. Securities that no longer meet the qualifying criteria during the course of the quarter remain in the Underlying Index until the next quarterly rebalancing date at which point they are dropped from the Underlying Index. It is not possible to invest directly in the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund's use of derivatives may result in losses to the Fund, a reduction in the Fund's returns and/or increased volatility. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction. Changes in regulation relating to a fund's use of derivatives and related instruments could potentially limit or impact the Fund's ability to invest in derivatives, limit the Fund's ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund's performance

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

The ICE BofAML Long US Treasury Principal STRIPS Index is an unmanaged index comprised of long maturity STRIPS representing the final principal payment of U.S. Treasury bonds. Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is -8.60%. For the periods shown in the bar chart, the highest quarterly return was 58.47% in the Q3 2011, and the lowest quarterly return was -18.24% in the Q4 2016.

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of The ICE BofAML 1-5 Year US Inflation-Linked Treasury Index.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities ("Component Securities") of The ICE BofAML 1-5 Year US Inflation-Linked Treasury Index (the "Underlying Index"). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which Pacific Investment Management Company LLC ("PIMCO") believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The dollar-weighted average portfolio maturity of this Fund will closely correspond to the average maturity of its Underlying Index, which as of September 30, 2018 was 3.07 years.

The Underlying Index is an unmanaged index comprised of Treasury Inflation-Protected Securities ("TIPS") with a maturity of at least 1 year and less than 5 years. TIPS are publicly issued, dollar denominated U.S. Government securities issued by the U.S. Treasury that have principal and interest payments linked to official inflation (as measured by the Consumer Price Index, or CPI). Their payments are supported by the full faith and credit of the United States. The TIPS in the Underlying Index have a minimum $1 billion of outstanding face value, have 1 to 5 years remaining to maturity and have interest and principal payments tied to inflation. Original issue zero coupon bonds can be included in the Underlying Index and the amounts outstanding of qualifying coupon securities are not reduced by any portions that have been stripped. As of September 30, 2018, there were 12 TIPS issues in the Underlying Index. The Underlying Index is capitalization-weighted and the composition of TIPS is updated monthly. Intra-month cash flows are reinvested daily, at the beginning-of-month 1-month LIBID rate, until the end of the month at which point all cash is removed from the Underlying Index. It is not possible to invest directly in the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Inflation-Indexed Security Risk: the risk that the value of an inflation-indexed security (such as TIPS) tends to decrease when real interest rates increase and increase when real interest rates decrease and interest payments on inflation-indexed securities will vary along with changes in the CPI

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

The ICE BofAML 1-5 Year US Inflation-Linked Treasury Index is an unmanaged index comprised of TIPS with a maturity of at least 1 year and less than 5 years. Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is 0.47%. For the periods shown in the bar chart, the highest quarterly return was 2.28% in the Q1 2011, and the lowest quarterly return was -2.89% in the Q2 2013.

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of The ICE BofAML 15+ Year US Inflation-Linked Treasury Index.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities ("Component Securities") of The ICE BofAML 15+ Year US Inflation-Linked Treasury Index (the "Underlying Index"). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which Pacific Investment Management Company LLC ("PIMCO") believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The dollar-weighted average portfolio maturity of this Fund will closely correspond to the average maturity of its Underlying Index, which as of September 30, 2018 was 24.99 years.

The Underlying Index is an unmanaged index comprised of Treasury Inflation-Protected Securities ("TIPS") with a maturity of at least 15 years. TIPS are publicly issued, dollar denominated U.S. Government securities issued by the U.S. Treasury that have principal and interest payments linked to official inflation (as measured by the Consumer Price Index, or CPI). Their payments are supported by the full faith and credit of the United States. The TIPS in the Underlying Index have a minimum $1 billion of outstanding face value, have at least 15 years remaining to maturity and have interest and principal payments tied to inflation. Original issue zero coupon bonds can be included in the Underlying Index and the amounts outstanding of qualifying coupon securities are not reduced by any portions that have been stripped. As of September 30, 2018, there were 9 TIPS issues in the Underlying Index. The Underlying Index is capitalization-weighted and the composition of TIPS is updated monthly. Intra-month cash flows are reinvested daily, at the beginning-of-month 1-month LIBID rate, until the end of the month at which point all cash is removed from the Underlying Index. It is not possible to invest directly in the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

The ICE BofAML 15+ Year US Inflation-Linked Treasury Index is an unmanaged index comprised of TIPS with a maturity of at least 15 years. Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is -4.68%. For the periods shown in the bar chart, the highest quarterly return was 12.67% in the Q3 2011, and the lowest quarterly return was -12.55% in the Q2 2013.

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of The ICE BofAML US Inflation-Linked Treasury Index.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities ("Component Securities") of The ICE BofAML US Inflation-Linked Treasury Index (the "Underlying Index"). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which Pacific Investment Management Company LLC ("PIMCO") believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public or private-sector entities. The dollar-weighted average portfolio maturity of this Fund will closely correspond to the average maturity of its Underlying Index, which as of September 30, 2018 was 8.76 years.

The Underlying Index is an unmanaged index comprised of Treasury Inflation-Protected Securities ("TIPS"). TIPS are publicly issued, dollar denominated U.S. Government securities issued by the U.S. Treasury that have principal and interest payments linked to official inflation (as measured by the Consumer Price Index, or CPI). Their payments are supported by the full faith and credit of the United States. The TIPS in the Underlying Index have a minimum $1 billion of outstanding face value, have at least 1 year remaining to maturity and have interest and principal payments tied to inflation. Original issue zero coupon bonds can be included in the Underlying Index and the amounts outstanding of qualifying coupon securities are not reduced by any portions that have been stripped. As of September 30, 2018, there were 39 TIPS issues in the Underlying Index. The Underlying Index is capitalization-weighted and the composition of TIPS is updated monthly. Intra-month cash flows are reinvested daily, at the beginning-of-month 1-month LIBID rate, until the end of the month at which point all cash is removed from the Underlying Index. It is not possible to invest directly in the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

The ICE BofAML US Inflation-Linked Treasury Index is an unmanaged index comprised of TIPS. Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is -1.19%. For the periods shown in the bar chart, the highest quarterly return was 5.08% in the Q3 2011, and the lowest quarterly return was -7.40% in the Q2 2013.

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of The ICE BofAML 0-5 Year US High Yield Constrained Index.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

1 "Other Expenses" include interest expense of 0.01%. Interest expense is borne by the Fund separately from the management fees paid to Pacific Investment Management Company LLC ("PIMCO"). Excluding interest expense, Total Annual Fund Operating Expenses are 0.55%.

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities ("Component Securities") of The ICE BofAML 0-5 Year US High Yield Constrained Index (the "Underlying Index"). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which PIMCO believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The average portfolio duration of this Fund will closely correspond to the portfolio duration of the securities comprising its Underlying Index, as calculated by PIMCO, which as of September 30, 2018 was 2.09 years. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates.

The Underlying Index is an unmanaged index comprised of U.S. dollar denominated below investment grade corporate debt securities publicly issued in the U.S. domestic market with remaining maturities of less than 5 years. Underlying Index constituents are capitalization-weighted, based on their current amount outstanding, provided the total allocation to an individual issuer does not exceed 2%. As of September 30, 2018, there were 851 issues in the Underlying Index. The securities comprising the Underlying Index have a below investment grade rating (based on an average of the ratings of Moody's Investors Service, Inc. ("Moody's"), Standard & Poor's Ratings Services ("S&P") and Fitch, Inc. ("Fitch")) and a country of risk exposure to investment grade countries that are members of the FXG10, Western Europe or territories of the U.S. and Western Europe. Country ratings are based on an average of Moody's, S&P and Fitch foreign currency long term sovereign debt ratings. For each issuer, the country of risk is the principal place of business derived from management location, country of primary listing, location of sales and reporting currency. In addition, qualifying securities must have a minimum $250 million of outstanding face value and a fixed coupon schedule. Original issue zero coupon bonds, debt issued simultaneously in the Eurobond and U.S. domestic bond markets, 144A securities and pay-in-kind securities qualify for inclusion in the Underlying Index. Callable perpetual securities qualify for inclusion in the Underlying Index provided they are at least one year from the first call date. Fixed-to-floating rate securities also qualify provided they are callable within the fixed rate period and are at least one year from last call prior to the date the bond transitions from a fixed to a floating rate security. The Underlying Index is capitalization-weighted, provided the total allocation to an individual issuer does not exceed 2%, and the composition of Component Securities is updated monthly. Cash flows from bond payments that are received during the month are retained in the Underlying Index, without earning reinvestment income, until removal at the end of the month as part of the rebalancing. It is not possible to invest directly in the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes.

indexing approach may eliminate the chance that the Fund will substantially outperform its Underlying Index but also may reduce some of the risks of active management. Indexing seeks to achieve lower costs by keeping portfolio turnover low in comparison to actively managed investment companies.

The Fund may invest in derivative instruments, such as options, futures contracts or swap agreements, and may invest in mortgage-related and other asset-backed securities. The Fund may invest in U.S. dollar-denominated securities of foreign issuers, including securities and instruments economically tied to emerging market countries. The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs). The "total return" sought by the Fund consists of income earned on the Fund's investments, plus capital appreciation, if any, which generally arises from decreases in interest rates.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund's use of derivatives may result in losses to the Fund, a reduction in the Fund's returns and/or increased volatility. Over-the-counter ("OTC") derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction. Changes in regulation relating to a fund's use of derivatives and related instruments could potentially limit or impact the Fund's ability to invest in derivatives, limit the Fund's ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund's performance

Emerging Markets Risk: the risk of investing in emerging market securities, primarily increased foreign (non-U.S.) investment risk

Sovereign Debt Risk: the risk that investments in fixed income instruments issued by sovereign entities may decline in value as a result of default or other adverse credit event resulting from an issuer's inability or unwillingness to make principal or interest payments in a timely fashion

losses and causing the Fund to be more volatile than if it had not been leveraged. This means that leverage entails a heightened risk of loss

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

The ICE BofAML 0-5 Year US High Yield Constrained Index tracks the performance of short-term U.S. dollar denominated below investment grade corporate debt issued in the U.S. domestic market with less than five years remaining term to final maturity, a fixed coupon schedule and a minimum amount outstanding of $250 million, issued publicly. Prior to September 30, 2016, securities with minimum amount outstanding of $100 million qualified. Allocations to an individual issuer will not exceed 2%. Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is 3.44%. For the periods shown in the bar chart, the highest quarterly return was 5.02% in the Q2 2016, and the lowest quarterly return was -4.17% in the Q3 2015.

For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial

intermediaries, please turn to the "Summary of Other Important Information Regarding Fund Shares" section on page 23 of this prospectus.

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of The ICE BofAML US Corporate Index.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities ("Component Securities") of The ICE BofAML US Corporate Index (the "Underlying Index"). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which PIMCO believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. "Fixed Income Instruments" include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The Fund may invest in securities rated Baa or higher by Moody's Investors Service, Inc. ("Moody's"), or equivalently rated by Standard & Poor's Ratings Services ("S&P") or Fitch, Inc. ("Fitch"), or, if unrated, determined by PIMCO to be of comparable quality. The average portfolio duration of this Fund will closely correspond to the portfolio duration of the securities comprising its Underlying Index, as calculated by PIMCO, which as of September 30, 2018 was 6.78 years. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates.

The Underlying Index is an unmanaged index comprised of U.S. dollar denominated investment grade corporate debt securities publicly issued in the U.S. domestic market with at least one year remaining term to final maturity. As of September 30, 2018, there were 7,818 issues in the Underlying Index. The securities comprising the Underlying Index have an investment grade rating (based on an average of the ratings of Moody's, S&P and Fitch) and an investment grade rated country of risk (based on an average of Moody's, S&P and Fitch foreign currency long term sovereign debt ratings). In addition, qualifying securities must have a minimum $250 million of outstanding face value and a fixed coupon schedule. Original issue zero coupon bonds, debt issued simultaneously in the Eurobond and U.S. domestic bond markets, 144A securities and corporate pay-in-kind securities qualify for inclusion in the Underlying Index. Callable perpetual securities qualify for inclusion in the Underlying Index provided they are at least one year from the first call date. Fixed-to-floating rate securities also qualify provided they are callable within the fixed rate period and are at least one year from last call prior to the date the bond transitions from a fixed to a floating rate security. The Underlying Index is capitalization-weighted and the composition of Component Securities is updated monthly. Cash flows from bond payments that are received during the month are retained in the Underlying Index, without earning reinvestment income, until removal at the end of the month as part of the rebalancing. It is not possible to invest directly in the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes.

The Fund may invest in derivative instruments, such as options, futures contracts or swap agreements, and may invest in mortgage related and other asset-backed securities. The Fund may invest in U.S. dollar-denominated securities of foreign issuers, including securities and instruments economically tied to emerging market countries. The Fund may purchase and sell securities on a when-issued, delayed delivery or forward

commitment basis. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs). The "total return" sought by the Fund consists of income earned on the Fund's investments, plus capital appreciation, if any, which generally arises from decreases in interest rates.

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Emerging Markets Risk: the risk of investing in emerging market securities, primarily increased foreign (non-U.S.) investment risk

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

The ICE BofAML US Corporate Index is an unmanaged index comprised of U.S. dollar denominated investment grade, fixed rate corporate debt securities publicly issued in the U.S. domestic market with at least one year remaining term to final maturity and at least $250 million outstanding. Performance is updated daily and quarterly and may be obtained at www.pimcoetfs.com/fundinfo.

*The year-to-date return as of September 30, 2018 is -2.41%. For the periods shown in the bar chart, the highest quarterly return was 4.41% in the Q1 2016, and the lowest quarterly return was -3.70% in the Q2 2013.

Each Fund is an exchange-traded fund ("ETF"). Individual Fund shares may only be purchased or sold on a national securities exchange through a broker-dealer and may not be purchased or redeemed directly with the Fund. The price of Fund shares is based on market price, and because ETF shares trade at market prices rather than net asset value ("NAV"), shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). The Funds will only issue or redeem shares at NAV that have been aggregated into blocks of 50,000 shares or multiples thereof ("Creation Units") with certain large institutional investors who have entered into agreements with the Funds' Distributor ("Authorized Participants"). The Fund will issue or redeem Creation Units in return for a basket of cash and/or securities that the Fund specifies each Business Day.

The Funds' distributions are generally taxable to you as ordinary income, capital gains, or a combination of the two, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account, in which case distributions may be taxable upon withdrawal.

If you purchase Fund shares through a broker-dealer or other financial intermediary, PIMCO or other related companies may pay the intermediary for the sale of Fund shares or related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

This prospectus describes seven ETFs (each a "Fund," collectively the "Funds") offered by PIMCO ETF Trust (the "Trust"). The Funds provide access to the professional investment advisory services offered by PIMCO. References to "the Fund" or "a Fund" relate to all Funds unless the context requires otherwise.

ETFs are funds that trade like other publicly-traded securities and may be designed to track an index or to be actively managed. Similar to shares of an index mutual fund, each share of the Fund represents a partial ownership of the fund which owns an underlying portfolio of securities intended to track an index. Unlike shares of a mutual fund, which can be bought from and redeemed by the issuing fund by all shareholders at a price based on NAV, shares of a Fund may be directly purchased from and redeemed by the Fund at NAV solely by Authorized Participants. Also unlike shares of a mutual fund, shares of ETFs are listed on a national securities exchange and trade in the secondary market at market prices that change throughout the day.

Once operational, shares of a Fund are listed and traded at market prices on NYSE Arca, Inc. ("NYSE Arca") and other secondary markets. The market price for a Fund's shares may be different from the Fund's NAV. The Funds issue and redeem shares at NAV only in Creation Units. Only Authorized Participants may purchase or redeem Creation Units directly with the Fund at NAV. These transactions are in exchange for securities and/or cash. Except when aggregated in Creation Units, shares of a Fund are not redeemable securities. Shareholders who are not Authorized Participants may not purchase or redeem shares directly from a Fund.

A Fund invests in a particular segment of the securities markets and seeks to track the performance of an index that is not representative of the broader securities markets. An investment in a particular Fund alone should not constitute an entire investment program. This prospectus explains what you should know about the Funds before you invest. Please read it carefully. Certain affiliates of the Funds and PIMCO may purchase and resell Fund shares pursuant to this prospectus.

Fund fact sheets provide additional information regarding the Funds and may be requested by calling 1.888.400.4ETF (1.888.400.4383).

The value of your investment in a Fund changes with the market price of the Fund's shares determined in the secondary market. Market price may be determined, in part, by the values of a Fund's investments. Many factors can affect those values. The factors that are most likely to have a material effect on a particular Fund's portfolio as a whole are called "principal risks." The principal risks of each Fund are identified in the Fund Summaries. The principal risks are described in more detail in this section. Each Fund may be subject to additional risks other than those identified and described below because the types of investments made by a Fund can change over time. Securities and investment techniques mentioned in this summary that appear in bold type are described in greater detail under "Characteristics and Risks of Securities and Investment Techniques." That section and "Investment Objectives and Policies" in the Statement of Additional Information (the "SAI") also include more information about the Funds, their investments and the related risks. There is no guarantee that a Fund will be able to achieve its investment objective. It is possible to lose money by investing in a Fund.

The value of inflation-indexed debt securities are subject to the effects of changes in real interest rates that may change as a result of different factors. In general, the value of an inflation-indexed security, including TIPS, tends to decrease when real interest rates increase and increase when real interest rates decrease. Interest payments on inflation-indexed securities will vary along with changes in the Consumer Price Index for All Urban Consumers (CPI-U) before seasonal adjustment (calculated by the Bureau of Labor Statistics). Thus generally, during periods of rising inflation, the value of inflation indexed securities will tend to increase and during periods of deflation, their value will tend to decrease. There can be no assurance that the inflation index used (i.e., CPI-U) will accurately measure the price increase of a certain good or service. Increases in the principal value of TIPS

due to inflation are considered taxable ordinary income for the amount of the increase in a calendar year.

A Fund could lose money if the issuer or guarantor of a fixed income security (including a security purchased with securities lending collateral), or the counterparty to a derivatives contract, repurchase agreement or a loan of portfolio securities, is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The downgrade of the credit of a security held by a Fund may decrease its value. Securities are subject to varying degrees of credit risk, which are often reflected in credit ratings. Measures such as average credit quality may not accurately reflect the true credit risk of a Fund. This is especially the case if a Fund consists of securities with widely varying credit ratings. Therefore, if a Fund has an average credit rating that suggests a certain credit quality, the Fund may in fact be subject to greater credit risk than the average would suggest. This risk is greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund. Municipal bonds are subject to the risk that litigation, legislation or other political events, local business or economic conditions, or the bankruptcy of the issuer could have a significant effect on an issuer's ability to make payments of principal and/or interest.

In such cases, a Fund, due to limitations on investments in illiquid securities and the difficulty in purchasing and selling such securities or instruments, may be unable to achieve its desired level of exposure to a certain sector. To the extent that a Fund's principal investment strategies involve securities of companies with smaller market capitalizations, foreign (non-U.S.) securities, Rule 144A securities, illiquid sectors of fixed income securities, derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to liquidity risk. Further, fixed income securities with longer durations until maturity face heightened levels of liquidity risk as compared to fixed income securities with shorter durations until maturity. Finally, liquidity risk also refers to the risk of unusually high redemption requests, redemption requests by certain large shareholders such as institutional investors or asset allocators, or other unusual market conditions that may make it difficult for a Fund to sell investments within the allowable time period to meet redemptions. Meeting such redemption requests could require a Fund to sell securities at reduced prices or under unfavorable conditions, which would reduce the value of the Fund. It may also be the case that other market participants may be attempting to liquidate fixed income holdings at the same time as a Fund, causing increased supply in the market and contributing to liquidity risk and downward pricing pressure.

Certain accounts or PIMCO affiliates may from time to time own (beneficially or of record) or control a significant percentage of a Fund's shares. Redemptions by these shareholders of their holdings in a Fund may impact the Fund's liquidity and NAV. These redemptions may also force a Fund to sell securities, which may negatively impact the Fund's brokerage costs.

Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. The various derivative instruments that the Funds may use are referenced under "Characteristics and Risks of Securities and Investment Techniques—Derivatives" in this prospectus and described in more detail under "Investment Objectives and Policies" in the SAI. The Funds typically use derivatives as a substitute for taking a position in the underlying asset, as part of strategies designed to gain exposure to, for example, issuers, portions of the yield curve, indexes, sectors, currencies, and/or geographic regions, and/or to reduce exposure to other risks, such as interest rate, credit, or currency risk. The Funds may also use derivatives for leverage, in which case their use would involve leveraging risk, and in some cases, may subject a Fund to the potential for unlimited loss. The use of derivatives may cause the Fund's investment returns to be impacted by the performance of securities the Fund does not own and result in the Fund's total investment exposure exceeding the value of its portfolio.

subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with a Fund's clearing broker, or the clearinghouse itself, rather than with a counterparty in an OTC derivative transaction.

The regulation of the derivatives markets has increased over the past several years, and additional future regulation of the derivatives markets may make derivatives more costly, may limit the availability or reduce the liquidity of derivatives, or may otherwise adversely affect the value or performance of derivatives. Any such adverse future developments could impair the effectiveness or raise the costs of a Fund's derivative transactions, impede the employment of the Fund's derivatives strategies, or adversely affect the Fund's performance.

Foreign (non-U.S.) investment risk may be particularly high to the extent a Fund invests in emerging market securities. Emerging market securities may present market, credit, currency, liquidity, legal, political and other risks different from, and potentially greater than, the risks of investing in securities and instruments economically tied to developed foreign countries. To the extent a Fund invests in emerging market securities that are economically tied to a particular region, country or group of countries, the Fund may be more sensitive to adverse political or social events affecting that region, country or group of countries. Economic, business, political, or social instability may affect emerging market securities differently, and often more severely, than developed market securities. A Fund that focuses its investments in multiple asset classes of emerging market securities may have a limited ability to mitigate losses in an environment that is adverse to emerging market securities in general. Emerging market securities may also be more volatile, less liquid and more difficult to value than securities economically tied to developed foreign countries. The systems and procedures for trading and settlement of securities in emerging markets are less developed and less transparent and transactions may take longer to settle. Rising interest rates, combined with widening credit spreads, could negatively impact the value of emerging market debt and increase funding costs for foreign issuers. In such a scenario, foreign issuers might not be able to service their debt obligations, the market for emerging market debt could suffer from reduced liquidity, and any investing Funds could lose money.

Sovereign debt risk is the risk that fixed income instruments issued by sovereign entities may decline in value as a result of default or other adverse credit event resulting from an issuer's inability or unwillingness to make principal or interest payments in a timely fashion. A sovereign entity's failure to make timely payments on its debt can result from many factors, including, without limitation, insufficient foreign currency reserves or an inability to sufficiently manage fluctuations in relative currency valuations, an inability or unwillingness to satisfy the demands of creditors and/or relevant supranational entities regarding debt service or economic reforms, the size of the debt burden relative to economic output and tax revenues, cash flow difficulties, and other political and social considerations. The risk of loss to the Fund in the event of a sovereign debt default or other adverse credit event is heightened by the unlikelihood of any formal recourse or means to enforce its rights as a holder of the sovereign debt. In addition, sovereign debt restructurings, which may be shaped by entities and factors beyond the Fund's control, may result in a loss in value of the Fund's sovereign debt holdings.

Certain transactions may give rise to a form of leverage. Such transactions may include, among others, reverse repurchase agreements, loans of portfolio securities and the use of when-issued, delayed delivery or forward commitment transactions. The use of derivatives may also create leveraging risk. In accordance with federal securities laws, rules and staff positions, PIMCO will mitigate its leveraging risk by segregating or "earmarking" liquid assets or otherwise covering transactions that may give rise to such risk. A Fund also may be exposed to leveraging risk by borrowing money for investment purposes. Leveraging may cause a Fund to liquidate portfolio positions to satisfy its obligations or to meet segregation requirements when it may not be advantageous to do so. Leveraging, including borrowing, may cause a Fund to be more volatile than if the Fund had not been leveraged. This is because leveraging tends to exaggerate the effect of any increase or decrease in the value of a Fund's portfolio securities. Certain types of leveraging transactions, such as short sales that are not "against the box," could theoretically be subject to unlimited losses in cases where a Fund, for any reason, is unable to close out the transaction. In addition, to the extent a Fund borrows money, interest costs on such borrowings may not be recovered by any appreciation of the securities purchased with the borrowed amounts and could exceed the Fund's investment returns, resulting in greater losses. Moreover, to make payments of interest and other loan costs, a Fund may be forced to sell portfolio securities when it is not otherwise advantageous to do so.

Each Fund is subject to management risk. PIMCO and each individual portfolio manager will apply investment techniques and risk analysis in making investment decisions for the Funds, but there can be no guarantee that these decisions will produce the desired results. Certain securities or other instruments in which a Fund seeks to invest may not be available in the quantities desired. In addition, regulatory restrictions, actual or potential conflicts of interest or other considerations may cause PIMCO to restrict or prohibit participation in certain investments. In such circumstances, PIMCO or the individual portfolio managers may determine to purchase other securities or instruments as substitutes. Such substitute securities or instruments may not perform as intended, which could result in losses to the Fund. Additionally, legislative, regulatory, or tax restrictions, policies or developments may affect the investment techniques available to PIMCO and each individual portfolio manager in connection with managing the Funds and may also adversely affect the ability of the Funds to achieve their investment objectives. There also can be no assurance that all of the personnel of PIMCO will continue to be associated with PIMCO for any length of time. The loss of services of one or more key employees of PIMCO could have an adverse impact on the Fund's ability to realize its investment objective.

A Fund may not invest in every component security of its underlying index. Imperfect correlation between a Fund's portfolio and its underlying index, asset valuation, timing variances, changes to the underlying index and regulatory requirements may cause the Fund's performance to diverge from the performance of its underlying index. Tracking error may also result because a Fund incurs fees and expenses while its underlying index does not incur such fees and expenses. Such expenses include the costs of buying and selling securities, such as when a Fund rebalances its portfolio to reflect changes in the composition of the underlying index. These expenses may be higher for a Fund investing in foreign (non-U.S.) securities. The performance of a Fund and the underlying index may vary due to differences between the Fund's portfolio and the underlying index due to legal restrictions, cost or liquidity restraints. The risk that performance of a Fund and the underlying index may vary may be heightened during periods of market volatility or other unusual market conditions. Because an underlying index is not subject to the tax diversification requirements to which a Fund must adhere, the Fund may be required to deviate its investments from the securities and relative weightings of its underlying index. For tax efficiency purposes, a Fund may sell certain securities to realize losses, which will result in a deviation from its underlying index. A Fund may not be fully invested at times either as a result of cash flows into the Fund or reserves of cash held by the Fund to meet redemptions and to pay expenses. In addition, a Fund's use of a representative sampling approach may cause the Fund to be less correlated with the return of the underlying index than if the Fund held all of the securities in the underlying index with the same relative weightings as the underlying index.

Each Fund uses an indexing approach and may be affected by a general decline in market segments or asset classes relating to its underlying index. A Fund invests in securities and instruments included in, or representative of, its underlying index regardless of the investment merits of the underlying index. Additionally, errors in the construction or calculation of a Fund's underlying index may occur from time to time, and the index provider may not identify or correct such errors for some period of time. Any such underlying index construction or calculation error may adversely impact the Fund.

Please see "Disclosure of Portfolio Holdings" in the SAI for information about the availability of the complete schedule of each Fund's holdings.

In addition to providing investment advisory services, PIMCO provides or procures supervisory and administrative services for shareholders and also bears the costs of various third-party services required by the Funds, including audit, custodial, portfolio accounting, legal, transfer agency and printing costs. The Funds bear other expenses which are not covered under the management fee which may vary and affect the total level of expenses paid by the shareholders, such as taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, securities lending expenses, extraordinary expenses (such as litigation and indemnification expenses) and fees and expenses of the Trust's Independent Trustees and their counsel. PIMCO generally earns a profit on the management fee paid by the Funds. Also, under the terms of the investment management agreement, PIMCO, and not Fund shareholders, would benefit from any price decreases in third-party services, including decreases resulting from an increase in net assets.

A discussion of the basis for the Board of Trustees' approval of the Funds' investment management agreement is available in the Funds' semi-annual report to shareholders for the fiscal half-year ended December 31, 2017.

The following individuals have primary responsibility for managing each of the noted Funds.

sometimes referred to as marketing support or revenue-sharing payments. An Intermediary may make decisions about which investment options it recommends or makes available, or the level of services provided, to its customers based on the marketing support payments it is eligible to receive. Therefore, such payments to an Intermediary create conflicts of interest between the Intermediary and its customers and may cause the Intermediary to recommend a Fund over another investment. More information regarding these payments is contained in the SAI. A shareholder should contact his or her Intermediary's salesperson or other investment professional for more information regarding any such payments the Intermediary firm may receive from PIMCO Entities.

Section 12(d)(1) of the 1940 Act restricts investments by registered investment companies in the securities of other investment companies. Registered investment companies are permitted to invest in the Funds beyond the limits set forth in Section 12(d)(1), subject to certain terms and conditions set forth in an SEC exemptive order issued to PIMCO and the Trust, including that such investment companies enter into an agreement with the Trust.

An index is a statistical composite that tracks a specified financial market or sector. Unlike a Fund, an index does not actually hold a portfolio of securities and therefore does not incur the expenses incurred by the Fund. These expenses negatively impact the performance of the Fund. Also, index returns do not include brokerage commissions that may be payable on secondary market transactions. If brokerage commissions were included, index returns would be lower. The index's returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or the redemption or sale of Fund shares. The investment return and principal value of shares of a Fund will vary with changes in market conditions. Shares of a Fund may be worth more or less than their original cost when they are redeemed or sold in the market.

For purposes of calculating NAV, portfolio securities and other assets for which market quotes are readily available are valued at market value. Market value is generally determined on the basis of official closing prices or the last reported sales prices, or if no sales are reported, based on quotes obtained from established market makers or prices (including evaluated prices) supplied by the Funds' approved pricing services, quotation reporting systems and other third-party sources (together, "Pricing Services"). The Funds will normally use pricing data for domestic equity securities received shortly after the NYSE Close and do not normally take into account trading, clearances or settlements that take place after the NYSE Close. A foreign (non-U.S.) equity security traded on a foreign exchange or on more than one exchange is typically valued using pricing information from the exchange considered by PIMCO to be the primary exchange. If market value pricing is used, a foreign (non-U.S.) equity security will be valued as of the close of trading on the foreign exchange, or the NYSE Close, if the NYSE Close occurs before the end of trading on the foreign exchange. Domestic and foreign (non-U.S.) fixed income securities, non-exchange traded derivatives, and equity options are normally valued on the basis of quotes obtained from brokers and dealers or Pricing Services using data reflecting the earlier closing of the principal markets for those securities. Prices obtained from Pricing Services may be based on, among other things, information provided by market makers or estimates of market values obtained from yield data relating to investments or securities with similar characteristics. Certain fixed income securities purchased on a delayed-delivery basis are marked to market daily until settlement at the forward settlement date. Exchange-traded options, except equity options, futures and options on futures are valued at the settlement price determined by the relevant exchange. Swap agreements are valued on the basis of bid quotes obtained from brokers and dealers or market-based prices supplied by Pricing Services or other pricing sources. With respect to any portion of a Fund's assets that are invested in one or more open-end management investment companies (other than ETFs), the Fund's NAV will be calculated based upon the NAVs of such investments.

securities. For these purposes, any movement in the applicable reference index or instrument ("zero trigger") between the earlier close of the applicable foreign market and the NYSE Close may be deemed to be a significant event, prompting the application of the pricing model (effectively resulting in daily fair valuations). Foreign (non-U.S.) exchanges may permit trading in foreign (non-U.S.) equity securities on days when the Trust is not open for business, which may result in a Fund's portfolio investments being affected when you are unable to buy or sell shares.

Senior secured floating rate loans for which an active secondary market exists to a reliable degree will be valued at the mean of the last available bid/ask prices in the market for such loans, as provided by a Pricing Service. Senior secured floating rate loans for which an active secondary market does not exist to a reliable degree will be valued at fair value, which is intended to approximate market value. In valuing a senior secured floating rate loan at fair value, the factors considered may include, but are not limited to, the following: (a) the creditworthiness of the borrower and any intermediate participants, (b) the terms of the loan, (c) recent prices in the market for similar loans, if any, and (d) recent prices in the market for instruments of similar quality, rate, period until next interest rate reset and maturity.

Investments valued in currencies other than the U.S. dollar are converted to the U.S. dollar using exchange rates obtained from Pricing Services. As a result, the value of such investments, and in turn, the NAV of the Fund's shares may be affected by changes in the value of currencies in relation to the U.S. dollar. The value of investments traded in markets outside the United States or denominated in currencies other than the U.S. dollar may be affected significantly on a day that the Trust is not open for business. As a result, to the extent that a Fund holds foreign (non-U.S.) investments, the value of those investments may change at times when shareholders are unable to buy or sell shares and the value of such investments will be reflected in the Fund's next calculated NAV. Investments for which market quotes or market based valuations are not readily available are valued at fair value as determined in good faith by the Board of Trustees or persons acting at their direction. The Board of Trustees has adopted methods for valuing securities and other assets in circumstances where market quotes are not readily available, and has delegated to PIMCO the responsibility for applying the fair valuation methods. In the event that market quotes or market based valuations are not readily available, and the security or asset cannot be valued pursuant to a Board approved valuation method, the value of the security or asset will be determined in good faith by the Valuation Oversight Committee of the Board of Trustees, generally based on recommendations provided by PIMCO. Market quotes are considered not readily available in circumstances where there is an absence of current or reliable market-based data (e.g., trade information, bid/ask information, broker quotes, Pricing Services' prices), including where events occur after the close of the relevant market, but prior to the NYSE Close, that materially affect the values of the Fund's securities or assets. In addition, market quotes are considered not readily available when, due to extraordinary circumstances, the exchanges or markets on which the securities trade do not open for trading for the entire day and no other market prices are available. The Board of Trustees has delegated to PIMCO the responsibility for monitoring significant events that may materially affect the values of the Fund's securities or assets and for determining whether the value of the applicable securities or assets should be reevaluated in light of such significant events.

Each Fund distributes substantially all of its net investment income to shareholders in the form of dividends. The Funds, except the PIMCO 25+ Year Zero Coupon U.S. Treasury Index Exchange-Traded Fund, intend to declare income dividends and distribute them monthly to shareholders of record. The PIMCO 25+ Year Zero Coupon U.S. Treasury Index Exchange-Traded Fund intends to declare and distribute income dividends quarterly to shareholders of record. In addition, each Fund distributes any net capital gains earned from the sale of portfolio securities to shareholders no less frequently than annually. Net short-term capital gains may be paid more frequently. Dividend payments are made through DTC participants and indirect participants to beneficial owners then of record with proceeds received from the Funds.

No dividend reinvestment service is provided by the Trust. Financial intermediaries may make available the DTC book-entry Dividend Reinvestment Service for use by beneficial owners of Fund shares for reinvestment of their dividend distributions. Beneficial owners should contact their financial intermediary to determine the availability and costs of the service and the details of participation therein. Financial intermediaries may require beneficial owners to adhere to specific procedures and timetables. If this service is available and used, dividend distributions of both income and net capital gains will automatically be reinvested in additional whole shares of a Fund purchased in the secondary market.

Taxes on Fund Distributions. If you are subject to U.S. federal income tax, you will be subject to tax on taxable Fund distributions. For federal income tax purposes, taxable Fund distributions will be taxable to you as either ordinary income or capital gains.

Fund distributions are taxable to you even if they are paid from income or gains earned by the Fund prior to your investment and thus were included in the price you paid for your shares. For example, if you purchase shares on or just before the record date of a Fund distribution, you will pay full price for the shares and may receive a portion of your investment back as a taxable distribution.

A Note on the PIMCO 1-5 Year U.S. TIPS Index Exchange-Traded Fund, the PIMCO 15+ Year U.S. TIPS Index Exchange-Traded Fund, and the PIMCO Broad U.S. TIPS Index Exchange-Traded Fund. Periodic adjustments for inflation to the principal amount of an inflation-indexed bond may give rise to original issue discount, which will be includable in a Fund's gross income. Due to original issue discount, a Fund may be required to make annual distributions to shareholders that exceed the cash received, which may cause the Fund to liquidate certain investments when it is not advantageous to do so. Also, if the principal value of an inflation-indexed bond is adjusted downward due to deflation, amounts previously distributed in the taxable year of such adjustment may be characterized in some circumstances as a return of capital.

Important Tax Reporting Considerations. The Internal Revenue Code of 1986 requires reporting of adjusted cost basis information for covered securities, which generally include shares of a regulated investment company acquired after January 1, 2012, to the Internal Revenue Service ("IRS") and to taxpayers. Shareholders should contact their financial intermediaries with respect to reporting of cost basis and available elections for their accounts.

Backup Withholding.Shareholders may be subject to U.S. federal income tax withholding with respect to distributions payable to shareholders if they fail to provide the Fund with their correct taxpayer identification number or to make required certifications, or if they have been notified by the IRS that they are subject to backup withholding. Backup withholding is not an additional tax. Any amounts withheld may be credited against U.S. federal income tax liability.

Foreign Withholding Taxes. A Fund may be subject to foreign withholding or other foreign taxes, which in some cases can be significant on any income or gain from investments in foreign securities. In that case, the Fund's total return on those securities would be decreased. Although in some cases the Fund may be able to apply for a refund of a portion of such taxes, the ability to successfully obtain such a refund may be uncertain. Each Fund may generally deduct these taxes in computing its taxable income. Rather than deducting these foreign taxes, a Fund that invests more than 50% of its assets in the stock or securities of foreign corporations or foreign governments at the end of its taxable year may make an election to treat a proportionate amount of eligible foreign taxes as constituting a taxable distribution to each shareholder, which would, subject to certain limitations, generally allow the shareholder to either (i) credit that proportionate amount of taxes against U.S. Federal income tax liability as a foreign tax credit or (ii) take that amount as an itemized deduction.

Foreign shareholders may be subject to U.S. tax withholding of 30% (or lower applicable treaty rate) on distributions from the Funds. Additionally, the Funds are required to withhold U.S. tax (at a 30% rate) on payments of taxable dividends as well as (effective January 1, 2019) redemption proceeds and certain capital gain dividends distributed to certain non-U.S. entities that fail to comply (or are deemed noncompliant) with extensive reporting and withholding requirements designed to inform the U.S. Department of the Treasury of U.S.-owned foreign investment accounts. Shareholders may be requested to provide additional information to enable the Funds to determine whether withholding is required.

This "Tax Consequences" section relates only to federal income tax; the consequences under other tax laws may differ. Shareholders should consult their tax advisors as to the possible application of foreign, state and local income tax laws to Fund dividends and capital distributions. Please see the "Taxation" in the SAI for additional information regarding the tax aspects of investing in the Funds.

This section provides additional information about some of the principal investments and related risks of the Funds described under "Fund Summaries" and "Description of Principal Risks" above. It also describes characteristics and risks of additional securities and investment techniques that may be used by the Funds from time to time. Most of these securities and investment techniques are discretionary, which means that PIMCO can decide whether to use them or not. This prospectus does not attempt to disclose all of the various types of securities and investment techniques that may be used by the Funds. As with any fund, investors in the Funds rely on the professional investment judgment and skill of PIMCO and the individual portfolio managers. Please see "Investment Objectives and Policies" in the SAI for more detailed information about the securities and investment techniques described in this section and about other strategies and techniques that may be used by the Funds.

Investors should be aware that the investments made by a Fund and the results achieved by a Fund at any given time are not expected to be the same as those made by other funds for which PIMCO acts as investment adviser, including funds with names, investment objectives and policies similar to a Fund. This may be attributable to a wide variety of factors, including, but not limited to, the use of a different portfolio management team or strategy, when a particular fund commenced operations or the size of a particular fund, in each case as compared to other similar funds. Significant purchases and redemptions of its Creation Units may adversely impact a Fund's portfolio management. For example, a Fund may be forced to sell a comparatively large portion of its portfolio to meet significant Creation Unit redemptions for cash, or hold a comparatively large portion of its portfolio in cash due to significant Creation Unit purchases for cash, in each case when the Fund otherwise would not seek to do so. Such transactions may cause Funds to make investment decisions at inopportune times or prices or miss attractive investment opportunities. Such transactions may also accelerate the realization of taxable income if sales of securities resulted in gains and the Fund redeems Creation Units for cash, or otherwise cause a Fund to perform differently than intended. Similarly, significant purchases of its Creation Units for cash may adversely affect a Fund's performance to the extent the Fund is delayed in investing new cash and, as a result, holds a proportionally larger cash position than under ordinary circumstances. While such risks may apply to Funds of any size, such risks are heightened in Funds with fewer assets under management. In addition, new Funds may not be able to fully implement their investment strategy immediately upon commencing investment operations, which could reduce investment performance.

Certain PIMCO-advised funds (the "PIMCO Funds of Funds") invest substantially all or a significant portion of their assets in other PIMCO-advised funds, including the Funds ("Underlying PIMCO Funds"). In some cases, the PIMCO Funds of Funds and certain funds managed by investment advisers affiliated with PIMCO ("Affiliated Funds of Funds") may be the predominant or sole shareholders of a particular Underlying PIMCO Fund. Investment decisions made with respect to the PIMCO Funds of Funds and Affiliated Funds of Funds could, under certain circumstances, negatively impact the Underlying PIMCO Funds with respect to the expenses and investment performance of the Underlying PIMCO Funds. For instance, large purchases or redemptions of exchange-traded shares of a Fund by the PIMCO Funds of Funds and Affiliated Funds of Funds, whether as part of a reallocation or rebalancing strategy or otherwise, may indirectly result in the Underlying PIMCO Fund having to sell securities or invest cash when it otherwise would not do so. Such transactions could increase an Underlying PIMCO Fund's transaction costs and accelerate the realization of taxable income if sales of securities resulted in gains and the Fund redeems Creation Units for cash. Additionally, as the PIMCO Funds of Funds and Affiliated Funds of Funds may invest substantially all or a significant portion of their assets in Underlying PIMCO Funds, the Underlying PIMCO Funds may not acquire securities of other registered open-end investment companies in reliance on Section 12(d)(1)(F) or Section 12(d)(1)(G) of the 1940 Act, thus limiting the Underlying PIMCO Funds' investment flexibility.

Each Fund seeks total return that closely corresponds, before fees and expenses, to the total return of the Funds' underlying index. The "total return" sought by a Fund consists of both income earned on a Fund's investments and capital appreciation, if any, arising from increases in the market value of a Fund's holdings. Capital appreciation of fixed income securities generally results from decreases in market interest rates, foreign currency appreciation, or improving credit fundamentals for a particular sector or security. Capital appreciation of inflation-linked bonds, such as TIPS, generally results from decreases in real interest rates and increased inflation.

In selecting securities and instruments for a Fund, PIMCO seeks to track the component securities of a Fund's underlying index. PIMCO may invest in a combination of component securities and other investments, or in component securities but in different proportions as compared to the weighting of the underlying index, such that the portfolio effectively provides exposure to the underlying index. When using a representative sampling strategy, PIMCO attempts to match the risk and return characteristics of a Fund's portfolio to the risk and return characteristics of a Fund's underlying index. PIMCO subdivides the underlying index into small categories of securities with similar features and characteristics. PIMCO generally divides the underlying index into parameters that determine a particular bond's risk and expected return (e.g., duration, sector, credit rating, coupon, and the presence of any embedded options). After each security in the underlying index is assigned to a subcategory, PIMCO begins to construct a Fund's portfolio by selecting representative bonds from each subcategory. The representative sample of bonds chosen from each subcategory is intended to closely correlate to the duration, sector, credit rating, coupon and option characteristics of the underlying index as a whole.

There are many potential benefits to using a representative sampling strategy with respect to a Fund. For example, PIMCO can avoid bonds that are relatively expensive (i.e., bonds that trade at perceived higher prices or lower yields due to supply demand) but have the same relative risk, value, duration and other characteristics as less expensive bonds. In addition, the use of sampling techniques permit PIMCO to exclude bonds that it believes will soon be deleted from the underlying index. PIMCO can also avoid holding bonds it deems less liquid than other bonds with similar characteristics which facilitates a more tradable portfolio. Furthermore, PIMCO can develop a basket of component securities that is easier to construct and less expensive to trade, thereby potentially improving arbitrage opportunities.

securities issued or guaranteed by the U.S. Government, its agencies or government-sponsored enterprises ("U.S. Government Securities");

corporate debt securities of U.S. and non-U.S. issuers, including convertible securities and corporate commercial paper;

structured notes, including hybrid or "indexed" securities and event-linked bonds;

repurchase agreements on Fixed Income Instruments and reverse repurchase agreements on Fixed Income Instruments;

debt securities issued by states or local governments and their agencies, authorities and other government-sponsored enterprises;

obligations of non-U.S. governments or their subdivisions, agencies and government-sponsored enterprises; and

Securities issued by U.S. Government agencies or government-sponsored enterprises may not be guaranteed by the U.S. Treasury.

The Funds, to the extent permitted by the 1940 Act, or exemptive relief therefrom, may invest in derivatives based on Fixed Income Instruments.

Each Fund may be subject to the risk that the returns of the Fund will decline during periods of falling interest rates because the Fund may have

to reinvest the proceeds from matured, traded or called debt obligations at interest rates below the Fund's current earnings rate. For instance, when interest rates decline, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, thereby forcing the Fund to invest in lower-yielding securities. A Fund also may choose to sell higher-yielding portfolio securities and to purchase lower-yielding securities to achieve greater portfolio diversification, because the Fund's portfolio manager believes the current holdings are overvalued or for other investment-related reasons. A decline in the returns received by a Fund from its investments is likely to have an adverse effect on the Fund's NAV, yield and total return.

Certain Funds may invest in fixed- and floating-rate loans, which investments generally will be in the form of loan participations and assignments of portions of such loans. Participations and assignments involve special types of risk, including credit risk, interest rate risk, liquidity risk, and the risks of being a lender. If a Fund purchases a participation, it may only be able to enforce its rights through the lender, and may assume the credit risk of the lender in addition to the borrower.

Securities rated lower than Baa by Moody's, or equivalently rated by S&P or Fitch, are sometimes referred to as "high yield securities" or "junk bonds." Issuers of these securities may be distressed and undergoing restructuring, bankruptcy or other proceedings in an attempt to avoid insolvency. Investing in these securities involves special risks in addition to the risks associated with investments in higher-rated fixed income securities. While offering a greater potential opportunity for capital appreciation and higher yields, high yield and distressed company securities typically entail greater potential price volatility and may be less liquid than higher-rated securities. High yield securities and debt securities of distressed companies may be regarded as predominately speculative with respect to the issuer's continuing ability to meet principal and interest payments. They may also be more susceptible to real or perceived adverse economic and competitive industry conditions than higher-rated securities. Certain Funds may invest in securities that are in default with respect to the payment of interest or repayment of principal, or present an imminent risk of default with respect to such payments. Issuers of securities in default may fail to resume principal or interest payments, in which case a Fund may lose its entire investment.

Variable and floating rate securities are securities that pay interest at rates that adjust whenever a specified interest rate changes and/or that reset on predetermined dates (such as the last day of a month or a calendar quarter). Certain Funds may invest in floating rate debt instruments ("floaters") and engage in credit spread trades. Variable and floating rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. Conversely, floating rate securities will not generally increase in value if interest rates decline. Certain Funds may also invest in inverse floating rate debt instruments ("inverse floaters"). An inverse floater may exhibit greater price volatility than a fixed rate obligation of similar credit quality. Certain Funds may invest up to 5% of its total assets in any combination of mortgage-related or other asset-backed IO, PO or inverse floater securities. Residual interest bonds are a type of inverse floater.

less liquid than conventional TIPS because they are a small component of the TIPS market.

Municipal inflation-indexed securities are municipal bonds that pay coupons based on a fixed rate plus CPI. With regard to municipal inflation-indexed bonds and certain corporate inflation-indexed bonds, the inflation adjustment is reflected in the semi-annual coupon payment. As a result, the principal value of municipal inflation-indexed bonds and such corporate inflation-indexed bonds does not adjust according to the rate of inflation. At the same time, the value of municipal inflation-indexed securities and such corporate inflation-indexed securities generally will not increase if the rate of inflation decreases. Because municipal inflation-indexed securities and corporate inflation-indexed securities are a small component of the municipal bond and corporate bond markets, respectively, they may be less liquid than conventional municipal and corporate bonds.

The value of inflation-indexed bonds is expected to change in response to changes in real interest rates. Real interest rates are tied to the relationship between nominal interest rates and the rate of inflation. If nominal interest rates increase at a faster rate than inflation, real interest rates may rise, leading to a decrease in value of inflation-indexed bonds. Any increase in the principal amount of an inflation-indexed bond will be considered taxable ordinary income, even though investors do not receive their principal until maturity.

Each Fund may obtain event-linked exposure by investing in "event-linked bonds" or "event-linked swaps" or by implementing "event-linked strategies." Event-linked exposure results in gains or losses that typically are contingent, or formulaically related to defined trigger events. Examples of trigger events include hurricanes, earthquakes, weather-related phenomena, or statistics related to such events. Some event-linked bonds are commonly referred to as "catastrophe bonds." If a trigger event occurs, a Fund may lose a portion or its entire principal invested in the bond or notional amount on a swap. Event-linked exposure often provides for an extension of maturity to process and audit loss claims where a trigger event has, or possibly has, occurred. An extension of maturity may increase volatility. Event-linked exposure may also expose a Fund to certain unanticipated risks including counterparty risk, adverse regulatory or jurisdictional interpretations, and adverse tax consequences. Event-linked exposures may also be subject to liquidity risk.

The PIMCO 0-5 Year High Yield Corporate Bond Index Exchange-Traded and the PIMCO Investment Grade Corporate Bond Index Exchange-Traded Funds may invest in securities and instruments that are economically tied to foreign (non-U.S.) countries. PIMCO generally considers an instrument to be economically tied to a non-U.S. country if the issuer is a foreign (non-U.S.) government (or any political subdivision, agency, authority or instrumentality of such government), or if the issuer is organized under the laws of a non-U.S. country. A Fund's investments in foreign (non-U.S.) securities may include American Depositary Receipts ("ADRs"), European Depositary Receipts ("EDRs"), Global Depositary Receipts ("GDRs") and similar securities that represent interests in a non-U.S. company's securities that have been deposited with a bank or trust and that trade on a U.S. exchange or over-the-counter. ADRs, EDRs and GDRs may be less liquid or may trade at a different price than the underlying securities of the issuer. In the case of money market instruments other than commercial paper and certificates of deposit, such instruments will be considered economically tied to a non-U.S. country if the issuer of such money market instrument is organized under the laws of a non-U.S. country. In the case of commercial paper and certificates of deposit, such instruments will be considered economically tied to a non-U.S. country if the "country of exposure" of such instrument is a non-U.S. country, as determined by the criteria set forth below. With respect to derivative instruments, PIMCO generally considers such instruments to be economically tied to non-U.S. countries if the underlying assets are foreign currencies (or baskets or indexes of such currencies), or instruments or securities that are issued by foreign governments; or issuers organized under the laws of a non-U.S. country (or if the underlying assets are money market instruments other than commercial paper and certificates of deposit, the issuer of such money market instrument is organized under the laws of a non-U.S. country or, in the case of underlying assets that are commercial paper or certificates of deposit if the "country of exposure" of such money market instrument is a non-U.S. country). A security's "country of exposure" is determined by PIMCO using certain factors provided by a third-party analytical service provider. The factors are applied in order such that the first factor to result in the assignment of a country determines the "country of exposure." Both the factors and the order in which they are applied may change in the discretion of PIMCO. The current factors, listed in the order in which they are applied, are: (i) if an asset-backed or other collateralized security, the country in which the collateral backing the security is located; (ii) the "country of risk" of the issuer; (iii) if the security is guaranteed by the government of a country (or any political subdivision, agency, authority or instrumentality of such government), the country of the government or instrumentality providing the guarantee; (iv) the "country of risk" of the issuer's ultimate parent; or (v) the country where the issuer is organized or incorporated under the laws thereof. "Country of risk" is a separate four-part test determined by the following factors, listed in order of importance: (i) management location; (ii) country of primary listing; (iii) sales or revenue attributable to the country; and (iv) reporting currency of the issuer. Further, where a derivative instrument is exposed to an index, PIMCO generally considers the derivative to be economically tied to each country represented by the components of the underlying index pursuant to the criteria set forth in the preceding sentence.

Investing in foreign (non-U.S.) securities involves special risks and considerations not typically associated with investing in U.S. securities. Investors should consider carefully the substantial risks involved for Funds that invest in securities issued by foreign companies and governments of foreign countries. These risks include: differences in accounting, auditing and financial reporting standards; generally higher commission rates on foreign portfolio transactions; the possibility of nationalization, expropriation or confiscatory taxation; adverse changes in investment or exchange control regulations; and political instability. Individual foreign economies may differ favorably or unfavorably from the U.S. economy in such respects as growth of gross domestic product, rates of inflation, capital reinvestment, resources, self- sufficiency and balance of payments position. The securities markets, values of securities, yields and risks associated with

foreign (non-U.S.) securities markets may change independently of each other. Also, foreign (non-U.S.) securities and dividends and interest payable on those securities may be subject to foreign taxes, including taxes withheld from payments on those securities. Foreign (non-U.S.) securities often trade with less frequency and volume than domestic securities and therefore may exhibit greater price volatility. Investments in foreign (non-U.S.) securities may also involve higher custodial costs than domestic investments and additional transaction costs with respect to foreign currency conversions. Changes in foreign exchange rates also will affect the value of securities denominated or quoted in foreign currencies.

Emerging Market Securities. The PIMCO 0-5 Year High Yield Corporate Bond Index Exchange-Traded and PIMCO Investment Grade Corporate Bond Index Exchange-Traded Funds may invest in securities and instruments that are economically tied to developing (or "emerging market") countries. PIMCO generally considers an instrument to be economically tied to an emerging market country if: the issuer is organized under the laws of an emerging market country; the currency of settlement of the security is a currency of an emerging market country; the security is guaranteed by the government of an emerging market country (or any political subdivision, agency, authority or instrumentality of such government); for an asset-backed or other collateralized security, the country in which the collateral backing the security is located is an emerging market country; or the security's "country of exposure" is an emerging market country, as determined by the criteria set forth below. With respect to derivative instruments, PIMCO generally considers such instruments to be economically tied to emerging market countries if the underlying assets are currencies of emerging market countries (or baskets or indexes of such currencies), or instruments or securities that are issued or guaranteed by governments of emerging market countries or by entities organized under the laws of emerging market countries or if an instrument's "country of exposure" is an emerging market country. A security's "country of exposure" is determined by PIMCO using certain factors provided by a third-party analytical service provider. The factors are applied in order such that the first factor to result in the assignment of a country determines the "country of exposure." Both the factors and the order in which they are applied may change in the discretion of PIMCO. The current factors, listed in the order in which they are applied, are: (i) if an asset-backed or other collateralized security, the country in which the collateral backing the security is located; (ii) the "country of risk" of the issuer; (iii) if the security is guaranteed by the government of a country (or any political subdivision, agency, authority or instrumentality of such government), the country of the government or instrumentality providing the guarantee; (iv) the "country of risk" of the issuer's ultimate parent; or (v) the country where the issuer is organized or incorporated under the laws thereof. "Country of risk" is a separate four-part test determined by the following factors, listed in order of importance: (i) management location; (ii) country of primary listing; (iii) sales or revenue attributable to the country; and (iv) reporting currency of the issuer. PIMCO has broad discretion to identify countries that it considers to qualify as emerging markets. In making investments in emerging market securities, a Fund emphasizes those countries with relatively low gross national product per capita and with the potential for rapid economic growth. Emerging market countries are generally located in Asia, Africa, the Middle East, Latin America and Eastern Europe. PIMCO will select the country and currency composition based on its evaluation of relative interest rates, inflation rates, exchange rates, monetary and fiscal policies, trade and current account balances, legal and political developments and any other specific factors it believes to be relevant.

Investing in emerging market securities imposes risks different from, or greater than, risks of investing in domestic securities or in foreign, developed countries. These risks include: smaller market capitalization of securities markets, which may suffer periods of relative illiquidity; significant price volatility; restrictions on foreign investment; possible repatriation of investment income and capital. In addition, foreign investors may be required to register the proceeds of sales; future economic or political crises could lead to price controls, forced mergers, expropriation or confiscatory taxation, seizure, nationalization, or creation of government monopolies. The currencies of emerging market countries may experience significant declines against the U.S. dollar, and devaluation may occur subsequent to investments in these currencies by a Fund. Many emerging market countries have experienced substantial, and in some periods extremely high, rates of inflation for many years. Inflation and rapid fluctuations in inflation rates have had, and may continue to have, negative effects on the economies and securities markets of certain emerging market countries. Additional risks of emerging market securities may include: greater social, economic and political uncertainty and instability; more substantial governmental involvement in the economy; less governmental supervision and regulation; unavailability of currency hedging techniques; companies that are newly organized and small; differences in auditing and financial reporting standards, which may result in unavailability of material information about issuers; and less developed legal systems. In addition, emerging securities markets may have different clearance and settlement procedures, which may be unable to keep pace with the volume of securities transactions or otherwise make it difficult to engage in such transactions. Settlement problems may cause a Fund to miss attractive investment opportunities, hold a portion of its assets in cash pending investment, or be delayed in disposing of a portfolio security. Such a delay could result in possible liability to a purchaser of the security.

Direct investments in foreign (non-U.S.) currencies or in securities that trade in, or receive revenues in, foreign (non-U.S.) currencies will be subject to currency risk. Foreign currency exchange rates may fluctuate significantly

over short periods of time. They generally are determined by supply and demand in the foreign exchange markets and the relative merits of investments in different countries, actual or perceived changes in interest rates and other complex factors. Currency exchange rates also can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign governments or central banks, or by currency controls or political developments. Currencies in which the Funds' assets are denominated may be devalued against the U.S. dollar, resulting in a loss to the Funds.

Foreign Currency Transactions. Funds that invest in securities denominated in foreign (non-U.S.) currencies may engage in foreign currency transactions on a spot (cash) basis, enter into forward foreign currency exchange contracts and invest in foreign currency futures contracts and options on foreign currencies and futures. A forward foreign currency exchange contract, which involves an obligation to purchase or sell a specific currency at a future date at a price set at the time of the contract, reduces a Fund's exposure to changes in the value of the currency it will deliver and increases its exposure to changes in the value of the currency it will receive for the duration of the contract. Certain foreign currency transactions may also be settled in cash rather than the actual delivery of the relevant currency. The effect on the value of a Fund is similar to selling securities denominated in one currency and purchasing securities denominated in another currency. Foreign currency transactions, like currency exchange rates, can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign governments or central banks, or by currency controls or political developments. Such events may prevent or restrict a Fund's ability to enter into foreign currency transactions, force the Fund to exit a foreign currency transaction at a disadvantageous time or price or result in penalties for the Fund, any of which may result in a loss to the Fund. A contract to sell a foreign currency would limit any potential gain which might be realized if the value of the hedged currency increases. A Fund may enter into these contracts to hedge against foreign exchange risk, to increase exposure to a foreign currency or to shift exposure to foreign currency fluctuations from one currency to another. Suitable hedging transactions may not be available in all circumstances and there can be no assurance that a Fund will engage in such transactions at any given time or from time to time. Also, such transactions may not be successful and may eliminate any chance for a Fund to benefit from favorable fluctuations in relevant foreign currencies. A Fund may use one currency (or a basket of currencies) to hedge against adverse changes in the value of another currency (or a basket of currencies) when exchange rates between the two currencies are positively correlated. A Fund will segregate or "earmark" assets determined to be liquid by PIMCO in accordance with the procedures established by the Board of Trustees (or, as permitted by applicable law, enter into certain offsetting positions) to cover its obligations under forward foreign currency exchange contracts.

certain other PIMCO funds in inter-fund lending transactions to the extent permitted by an exemptive order from the SEC.

Each Fund may, but is not required to, use derivative instruments for risk management purposes or as part of its investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate or index, and may relate to stocks, bonds, interest rates, spreads between different interest rates, currencies or currency exchange rates, commodities, and related indexes. Examples of derivative instruments include options contracts, futures contracts, options on futures contracts and swap agreements (including, but not limited to, credit default swaps and swaps on ETFs). Each Fund may invest some or all of its assets in derivative instruments, subject to the Fund's objective and policies. A portfolio manager may decide not to employ any of these strategies and there is no assurance that any derivatives strategy used by a Fund will succeed. A description of these and other derivative instruments that the Funds may use are described under "Investment Objectives and Policies" in the SAI.

CPI Swap. A CPI swap is a fixed maturity, over-the-counter derivative transaction in which the investor receives the "realized" rate of inflation as measured by the CPI over the life of the swap. The investor in turn pays a fixed annualized rate over the life of the swap. This fixed rate is often referred to as the "breakeven inflation" rate and is generally representative of the difference between treasury yields and TIPS yields of similar maturities at the initiation of the swap. CPI swaps are typically in "bullet" format, where all cash flows are exchanged at maturity. In addition to counterparty risk, CPI swaps are also subject to inflation risk, where the swap can potentially lose value if the realized rate of inflation over the life of the swap is less than the fixed market implied inflation rate (fixed breakeven rate) that the investor agrees to pay at the initiation of the swap.

Lack of Availability. Because the markets for certain derivative instruments (including markets located in foreign countries) are relatively new and still developing, suitable derivatives transactions may not be available in all circumstances for risk management or other purposes. Upon the expiration of a particular contract, a portfolio manager may wish to retain a Fund's position in the derivative instrument by entering into a similar contract, but may be unable to do so if the counterparty to the original contract is unwilling to enter into the new contract and no other suitable counterparty can be found. There is no assurance that a Fund will engage in derivatives transactions at any time or from time to time. A Fund's ability to use derivatives may also be limited by certain regulatory and tax considerations.

Correlation Risk. In certain cases, the value of derivatives may not correlate perfectly, or at all, with the value of the assets, reference rates or indexes they are designed to closely track. For example, a swap agreement on an ETF would not correlate perfectly with the index upon which the ETF is based because the fund's return is net of fees and expenses. In this regard, a Fund may seek to achieve its investment objective, in part, by investing in derivatives positions that are designed to closely track the performance (or inverse performance) of an index on a daily basis. However, the overall investment strategies of the Fund are not designed or expected to produce returns which replicate the performance (or inverse performance) of the particular index, and the degree of variation could be substantial, particularly over longer periods. There are a number of factors which may prevent a Fund, or derivatives or other strategies used by a Fund, from

achieving a desired correlation (or inverse correlation) with an index. These may include, but are not limited to: (i) the impact of fund fees, expenses and transaction costs, including borrowing and brokerage costs/bid-ask spreads, which are not reflected in index returns; (ii) differences in the timing of daily calculations of the value of an index and the timing of the valuation of derivatives, securities and other assets held by a Fund and the determination of the NAV of Fund shares; (iii) disruptions or illiquidity in the markets for derivative instruments or securities in which a Fund invests; (iv) a Fund having exposure to or holding less than all of the securities in the underlying index and/or having exposure to or holding securities not included in the underlying index; (v) large or unexpected movements of assets into and out of a Fund (due to share purchases or redemptions, for example), potentially resulting in the Fund being over- or under-exposed to the index; (vi) the impact of accounting standards or changes thereto; (vii) changes to the applicable index that are not disseminated in advance; (viii) a possible need to conform a Fund's portfolio holdings to comply with investment restrictions or policies or regulatory or tax law requirements; and (ix) fluctuations in currency exchange rates.

Market and Other Risks. Like most other investments, derivative instruments are subject to the risk that the market value of the instrument will change in a way detrimental to a Fund's interest. If a portfolio manager incorrectly forecasts the values of securities, currencies or interest rates or other economic factors in using derivatives for a Fund, the Fund might have been in a better position if it had not entered into the transaction at all. While some strategies involving derivative instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other Fund investments. A Fund may also have to buy or sell a security at a disadvantageous time or price because the Fund is legally required to maintain offsetting positions or asset coverage in connection with certain derivatives transactions. The regulation of the derivatives markets has increased over the past several years, and additional future regulation of the derivatives markets may make derivatives more costly, may limit the availability or reduce the liquidity of derivatives, or may otherwise adversely affect the value or performance of derivatives. Any such adverse future developments could impair the effectiveness or raise the costs of a Fund's derivative transactions, or impede the employment of a Fund's derivatives strategies, or adversely affect a Fund's performance.

Other risks in using derivatives include the risk of mispricing or improper valuation of derivatives. Many derivatives, in particular privately negotiated derivatives, are complex and often valued subjectively. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a Fund. Also, the value of derivatives may not correlate perfectly, or at all, with the value of the assets, reference rates or indexes they are designed to closely track. For example, a swap agreement on an exchange-traded fund would not correlate perfectly with the index upon which the exchange-traded fund is based because the fund's return is net of fees and expenses. In addition, a Fund's use of derivatives may cause the Fund to realize higher amounts of short-term capital gains (generally taxed at ordinary income tax rates) than if the Fund had not used such instruments.

Each Fund may also enter into, or acquire participations in, delayed funding loans and revolving credit facilities, in which a lender agrees to make loans up to a maximum amount upon demand by the borrower during a specified term. These commitments may have the effect of requiring a Fund to increase its investment in a company at a time when it might not otherwise decide to do so (including at a time when the company's financial condition makes it unlikely that such amounts will be repaid). To the extent that a Fund is committed to advance additional funds, it will segregate or "earmark" assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees in an amount sufficient to meet such commitments. Delayed funding loans and revolving credit facilities are subject to credit, interest rate and liquidity risk and the risks of being a lender.

Each Fund may purchase or sell securities which it is eligible to purchase or sell on a when-issued basis, may purchase and sell such securities for delayed delivery and may make contracts to purchase or sell such securities for a fixed price at a future date beyond normal settlement time (forward commitments). When-issued transactions, delayed delivery purchases and forward commitments involve a risk of loss if the value of the securities declines prior to the settlement date. This risk is in addition to the risk that a Fund's other assets will decline in value. Therefore, these transactions may result in a form of leverage and increase a Fund's overall investment exposure. Typically, no income accrues on securities a Fund has committed to purchase prior to the time delivery of the securities is made, although a Fund may earn income on securities it has segregated or "earmarked" to cover these positions. When a Fund has sold a security on a when-issued, delayed delivery, or forward commitment basis, the Fund does not participate in future gains or losses with respect to the security. If the other party to a transaction fails to pay for the securities, a Fund could suffer a loss. Additionally, when selling a security on a when-issued, delayed delivery or forward commitment basis without owning the security, a Fund will incur a loss if the security's price appreciates in value such that the security's price is above the agreed-upon price on the settlement date.

Each Fund may invest in securities of other investment companies, such as open-end or closed-end management investment companies, including ETFs or in pooled accounts, or other unregistered accounts or investment vehicles to the extent permitted by the 1940 Act and the rules and regulations thereunder and any exemptive relief therefrom. A Fund may invest in other investment companies to gain broad market or sector exposure, including during periods when it has large amounts of uninvested cash or when PIMCO believes share prices of other investment companies offer attractive values. As a shareholder of an investment company or other pooled vehicle, a Fund may indirectly bear investment advisory fees, supervisory and administrative fees, service fees and other fees which are in addition to the fees the Fund pays its service providers.

Subject to the restrictions and limitations of the 1940 Act, each Fund may, in the future, elect to pursue its investment objective either by investing

directly in securities, or by investing in one or more underlying investment vehicles or companies that have substantially similar investment objectives and policies as the Fund.

Each Fund may invest up to 15% of its net assets (taken at the time of investment) in illiquid securities. Certain illiquid securities may require pricing at fair value as determined in good faith under the supervision of the Board of Trustees. A portfolio manager may be subject to significant delays in disposing of illiquid securities, and transactions in illiquid securities may entail registration expenses and other transaction costs that are higher than those for transactions in liquid securities. The term "illiquid securities" for this purpose means securities that cannot be disposed of within seven days in the ordinary course of business at approximately the amount at which a Fund has valued the securities. Restricted securities, i.e., securities subject to legal or contractual restrictions on resale, may be illiquid. However, some restricted securities (such as securities issued pursuant to Rule 144A under the Securities Act of 1933, as amended, and certain commercial paper) may be treated as liquid, although they may be less liquid than registered securities traded on established secondary markets.

For the purpose of achieving income, each Fund may lend its portfolio securities to brokers, dealers, and other financial institutions provided a number of conditions are satisfied, including that the loan is fully collateralized. Please see "Investment Objectives and Policies" in the SAI for details. When a Fund lends portfolio securities, its investment performance will continue to reflect changes in the value of the securities loaned, and the Fund will also receive a fee or interest on the collateral. Securities lending involves the risk of loss of rights in the collateral or delay in recovery of the collateral if the borrower fails to return the security loaned or becomes insolvent. A Fund may pay lending fees to a party arranging the loan. Cash collateral received by a Fund in securities lending transactions may be invested in short-term liquid fixed income instruments or in money market or short-term mutual funds, or similar investment vehicles, including affiliated money market or short-term mutual funds. A Fund bears the risk of such investments.

The length of time a Fund has held a particular security is not generally a consideration in investment decisions. A change in the securities held by a Fund is known as "portfolio turnover." When a portfolio manager deems it appropriate, and particularly during periods of volatile market movements, a Fund may engage in frequent and active trading of portfolio securities to achieve its investment objective, including, without limitation, to reflect changes in a Fund's Underlying Index, such as reconstitutions, additions or deletions of component securities. To the extent that Creation Unit purchases from and redemptions by a Fund are effected in cash, frequent purchases and redemptions may increase the rate of portfolio turnover. Higher portfolio turnover (e.g., an annual rate greater than 100% of the average value of a Fund's portfolio) involves correspondingly greater expenses to a Fund, including brokerage commissions or dealer markups and other transaction costs on the sale of securities and reinvestments in other securities. Such sales may also result in realization of taxable capital gains, including short-term capital gains (which are generally taxed at ordinary income tax rates). The trading costs and tax effects associated with portfolio turnover may adversely affect a Fund's performance. Please see a Fund's "Fund Summary—Portfolio Turnover" or the "Financial Highlights" in this prospectus for the portfolio turnover rates of the Funds that were operational during the last fiscal year. In addition, large movements of cash into or out of a Fund may negatively impact the Fund's ability to achieve its investment objective or maintain a consistent level of operating expenses.

heavily on the portfolio manager's creditworthiness analysis than if the Fund invested exclusively in higher-quality and rated securities.

As the use of technology has become more prevalent in the course of business, the Funds have become potentially more susceptible to operational and information security risks resulting from breaches in cyber security. A breach in cyber security refers to both intentional and unintentional cyber events that may, among other things, cause a Fund to lose proprietary information, suffer data corruption and/or destruction or lose operational capacity, result in the unauthorized release or other misuse of confidential information, or otherwise disrupt normal business operations. Cyber security breaches may involve unauthorized access to a Fund's digital information systems (e.g., through "hacking" or malicious software coding), but may also result from outside attacks such as denial-of-service attacks (i.e., efforts to make network services unavailable to intended users). In addition, cyber security breaches involving a Fund's third party service providers (including but not limited to advisers, sub-advisers, administrators, transfer agents, custodians, distributors and other third parties), trading counterparties or issuers in which a Fund invests can also subject a Fund to many of the same risks associated with direct cyber security breaches. Moreover, cyber security breaches involving trading counterparties or issuers in which a Fund invests could adversely impact such counterparties or issuers and cause the Fund's investment to lose value.

"ICE BofAML" and "The ICE BofAML 1-3 Year US Treasury Index," "The ICE BofAML Long US Treasury Principal STRIPS Index," "The ICE BofAML US Inflation-Linked Treasury Index," "The ICE BofAML 1-5 Year US Inflation-Linked Treasury Index," "The ICE BofAML 15+ Year US Inflation-Linked Treasury Index," "The ICE BofAML 0-5 Year US High Yield Constrained Index" and "The ICE BofAML US Corporate Index" (collectively, the "ICE BofAML Indexes") are reprinted with permission. ^© Copyright 2017 Merrill Lynch, Pierce, Fenner & Smith Incorporated ("ICE BofAML"). All rights reserved. "ICE BofAML" and the ICE BofAML Indexes are service marks of ICE BofAML and/or its affiliates and have been licensed for use for certain purposes by PIMCO on behalf of the Funds that are based on the ICE BofAML Indexes, and are not issued, sponsored, endorsed or promoted by ICE BofAML and/or ICE BofAML's affiliates nor is ICE BofAML and/or ICE BofAML's affiliates an adviser to the Funds. ICE BofAML and ICE BofAML's affiliates make no representation, express or implied, regarding the advisability of investing in the Funds or the ICE BofAML Indexes and do not guarantee the quality, accuracy or completeness of the ICE BofAML Indexes, index values or any index related data included herein, provided herewith or derived therefrom and assume no liability in connection with their use. As the index provider, ICE BofAML is licensing certain trademarks, the ICE BofAML Indexes and trade names which are composed by ICE BofAML without regard to PIMCO, the Funds or any investor. ICE BofAML and ICE BofAML's affiliates do not provide investment advice to PIMCO or the Funds and are not responsible for the performance of the Funds. ICE BofAML compiles and publishes the ICE BofAML Indexes. PIMCO has entered into a license agreement with ICE BofAML to use each Underlying Index.

There is no guarantee that ICE BofAML will permit PIMCO to use each Underlying Index beyond the term of the current license agreement. In the event that ICE BofAML terminates or chooses not to renew the license agreement, each Fund will cease use of its Underlying Index and will seek to achieve its investment objective by investing in the component securities of a comparable index. Neither the Trust, the Funds, PIMCO nor the Distributor guarantees the accuracy or the completeness of the ICE BofAML Indexes or any data included therein and neither the Trust, the Funds, PIMCO nor the Distributor shall have liability for any errors, omissions or interruptions therein.

The Trust, the Funds, PIMCO and the Distributor make no warranty, express or implied, to the owners of shares of the Funds or to any other person or entity, as to results to be obtained by the Funds from the use of the ICE BofAML Indexes or any data included therein. The Trust, the Funds, PIMCO and the Distributor make no express or implied warranties and expressly disclaim all warranties of merchantability or fitness for a particular purpose or use with respect to the ICE BofAML Indexes or any data included therein. Without limiting any of the foregoing, in no event shall the Trust, the Funds, PIMCO or the Distributor have any liability for any special, punitive, direct,

indirect or consequential damages (including lost profits), even if notified of the possibility of such damages.

The Funds are not issued, sponsored, endorsed or promoted by ICE BofAML, any affiliate of ICE BofAML or any other party involved in, or related to, making or compiling the ICE BofAML Indexes. The ICE BofAML Indexes are the exclusive property of ICE BofAML and/or its affiliates. "ICE BofAML" and "The ICE BofAML 1-3 Year US Treasury Index," "The ICE BofAML Long US Treasury Principal STRIPS Index," "The ICE BofAML US Inflation-Linked Treasury Index," "The ICE BofAML 1-5 Year US Inflation-Linked Treasury Index," "The ICE BofAML 15+ Year US Inflation-Linked Treasury Index," "The ICE BofAML 0-5 Year US High Yield Constrained Index" and "The ICE BofAML US Corporate Index" (the "ICE BofAML Indexes") are reprinted with permission. © Copyright 2017 Merrill Lynch, Pierce, Fenner & Smith Incorporated. The ICE BofAML Indexes are service marks of ICE BofAML and/ or its affiliates and have been licensed for use for certain purposes by PIMCO on behalf of the Funds. Neither ICE BofAML, any affiliate of ICE BofAML nor any other party involved in, or related to, making or compiling the ICE BofAML Indexes makes any representation or warranty, express or implied, to the shareholders of the Funds or any member of the public regarding the advisability of investing in securities generally or in the Funds particularly or the ability of the ICE BofAML Indexes to track the corresponding market performance. ICE BofAML is the licensor of certain trademarks, trade names and service marks of ICE BofAML and/or its affiliates and of the ICE BofAML Indexes, which are determined, composed and calculated by ICE BofAML and/or its affiliates without regard to PIMCO, the Funds or the shareholders of the Funds. Neither ICE BofAML, any affiliate of ICE BofAML nor any other party involved in, or related to, making or compiling the ICE BofAML Indexes has any obligation to take the needs of PIMCO, the Funds or the shareholders of the Funds into consideration in determining, composing or calculating the ICE BofAML Indexes. None of ICE BofAML or any of its affiliates have the obligation to continue to provide the ICE BofAML Indexes to PIMCO or the Funds beyond the applicable license term. Neither ICE BofAML, any affiliate of ICE BofAML nor any other party involved in, or related to, making or compiling the ICE BofAML Indexes is responsible for or has participated in the determination of the timing, pricing, or quantities of the Funds to be issued or in the determination or calculation of the equation by which the Funds are to be redeemable. Neither ICE BofAML, any affiliate of ICE BofAML nor any other party involved in, or related to, making or compiling the ICE BofAML Indexes has any obligation or liability in connection with the administration, marketing or trading of the Funds. ICE BofAML and its affiliates do not provide investment advice to PIMCO or the Funds and are not responsible for the performance of the Funds.

NEITHER ICE BofAML, ANY AFFILIATE OF ICE BofAML NOR ANY OTHER PARTY INVOLVED IN, OR RELATED TO, MAKING OR COMPILING THE ICE BofAML INDEXES WARRANTS OR GUARANTEES THE ACCURACY AND/OR THE COMPLETENESS OF THE ICE BofAML INDEXES OR ANY DATA INCLUDED THEREIN AND/OR PROVIDED THEREWITH AND SHALL HAVE NO LIABILITY FOR ANY ERRORS, OMISSIONS, OR INTERRUPTIONS THEREIN. NEITHER ICE BofAML, ANY AFFILIATE OF ICE BofAML NOR ANY OTHER PARTY INVOLVED IN, OR RELATED TO, MAKING OR COMPILING THE ICE BofAML INDEXES MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY PIMCO, THE FUNDS, SHAREHOLDERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE ICE BofAML INDEXES OR ANY DATA INCLUDED THEREIN. NEITHER ICE BofAML, ANY AFFILIATE OF ICE BofAML NOR ANY OTHER PARTY INVOLVED IN, OR RELATED TO, MAKING OR COMPILING THE ICE BofAML INDEXES MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE ICE BofAML INDEXES OR ANY DATA INCLUDED THEREIN AND/OR PROVIDED THEREWITH. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL ICE BofAML, ANY AFFILIATE OF ICE BofAML OR ANY OTHER PARTY INVOLVED IN, OR RELATED TO, MAKING OR COMPILING THE ICE BofAML INDEXES HAVE ANY LIABILITY FOR DIRECT, INDIRECT, PUNITIVE, SPECIAL, CONSEQUENTIAL OR ANY OTHER DAMAGES OR LOSSES (INCLUDING LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY THEREOF. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN ICE BofAML AND PIMCO.

No purchaser, seller or holder of this security, or any other person or entity, should use or refer to any ICE BofAML trade name, trademark or service mark to sponsor, endorse, market or promote this product without first contacting ICE BofAML to determine whether ICE BofAML's permission is required. Under no circumstances may any person or entity claim any affiliation with ICE BofAML without the written permission of ICE BofAML.

Shares of the Funds are not sponsored, endorsed or promoted by NYSE Arca. NYSE Arca makes no representation or warranty, express or implied, to the owners of shares of the Funds or any member of the public regarding the ability of the Funds to track the total return performance of an Underlying Index or the ability of an Underlying Index to track fixed income performance. NYSE Arca is not responsible for, nor has it participated in, the determination of the compilation or the calculation of an Underlying Index, nor in the determination of the timing of, prices of or quantities of shares of the Funds to be issued, nor in the determination or calculation of the equation by which the shares are redeemable. NYSE Arca has no obligation or liability to owners of shares of the Funds in connection with the administration, marketing or trading of shares of the Funds. NYSE Arca does not guarantee the accuracy and/or the completeness of an Underlying Index or any data included therein. NYSE Arca makes no warranty, express or implied, as to results to be obtained by the Trust, on behalf of the Funds as licensee, licensee's customers and counterparties, owners of shares of the Funds or any other person or entity, from the use of an Underlying Index or any data included therein in connection with the rights licensed as described herein or for any other use.

NYSE Arca makes no express or implied warranties and hereby expressly disclaims all warranties of merchantability or fitness for a particular purpose with respect to an Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall NYSE Arca have any liability for any direct, indirect, special, punitive, consequential or any other damages (including lost profits) even if notified of the possibility of such damages.

The financial highlights table is intended to help a shareholder understand each Fund's financial performance for the last five fiscal years or, if shorter, the period since a Fund commenced operations. Certain information reflects financial results for a single Fund share. The total returns in the table represent the rate that an investor would have earned or lost on an investment in shares of a Fund (assuming reinvestment of all dividends and distributions). This information has been audited by PricewaterhouseCoopers LLP, whose report, along with each Fund's financial statements, are included in the Trust's annual report to shareholders. The annual report is available free of charge by calling the Trust at the phone number on the back of this prospectus. The annual report is also available for download free of charge on the Trust's web site at www.pimcoetfs.com. Note: All footnotes to the financial highlights table appear at the end of the tables.