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Janus Henderson Absolute Return Income Opportunities Fund

(formerly named Janus Henderson Global Unconstrained Bond Fund)

Ticker: JUCDX Class D Shares*

* Effective July 6, 2020, Class D Shares are open to new investors. Until that time, Class D Shares remain closed to new investors, with certain limited exceptions.

Summary Prospectus dated October 28, 2019
As Supplemented June 19, 2020

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus, reports to shareholders, and other information about the Fund online at janushenderson.com/reports. You can also get this information at no cost by calling a Janus Henderson representative at 1-800-525-3713 or by sending an email request to prospectusorder@janushenderson.com.

Beginning on January 1, 2021, as permitted by regulations adopted by the Securities and Exchange Commission, paper copies of the Fund’s shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund or your plan sponsor, broker-dealer, or financial intermediary, or if you invest directly with the Fund, by contacting a Janus Henderson representative. Instead, the reports will be made available on a website, and you will be notified by mail each time a report is posted and provided with a website link to access the report.

If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by contacting your plan sponsor, broker-dealer, or financial intermediary, or if you invest directly with the Fund, by visiting janushenderson.com/edelivery.

You may elect to receive all future reports in paper free of charge. If you do not invest directly with the Fund, you should contact your plan sponsor, broker-dealer, or financial intermediary, to request to continue receiving paper copies of your shareholder reports. If you invest directly with the Fund, you can call 1-800-525-3713 to let the Fund know that you wish to continue receiving paper copies of your shareholder reports. Your election to receive reports in paper will apply to all Janus Henderson mutual funds where held (i.e., all Janus Henderson mutual funds held in your account if you invest through your financial intermediary or all Janus Henderson mutual funds held with the fund complex if you invest directly with a fund).

Investment Objective

Janus Henderson Absolute Return Income Opportunities Fund seeks to maximize total return, consistent with preservation of capital.

Fees and Expenses of the Fund

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)	Class D
Management Fees	0.64%
Other Expenses	0.40%
Acquired Fund(1) Fees and Expenses	0.04%
Total Annual Fund Operating Expenses(2)	1.08%
Fee Waiver(2)	0.24%
Total Annual Fund Operating Expenses After Fee Waiver(2)	0.84%

(1)  “Acquired Fund” refers to any underlying fund (including, but not limited to, exchange-traded funds) in which a fund invests or has invested during the period. Acquired fund fees and expenses are indirect expenses a fund may incur as a result of investing in shares of an underlying fund. To the extent that the Fund invests in Acquired Funds, the Fund’s “Total Annual Fund Operating Expenses” may not correlate to the “Ratio of gross expenses to average net assets” presented in the Financial Highlights table because that ratio includes only the direct operating expenses incurred by the Fund, not the indirect costs of investing in Acquired Funds.

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(2)  Janus Capital has contractually agreed to waive its investment advisory fee and/or reimburse operating expenses to the extent that the Fund’s total annual fund operating expenses (excluding administrative services fees (including out-of-pocket costs), brokerage commissions, interest, dividends, taxes, acquired fund fees and expenses, and extraordinary expenses) exceed 0.63% for at least a one-year period commencing on October 28, 2019. The contractual waiver may be terminated or modified prior to this date only at the discretion of the Board of Trustees.

EXAMPLE:

The following Example is based on expenses without waivers. The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, reinvest all dividends and distributions, and then redeem all of your Shares at the end of each period. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses without waivers remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class D Shares	$ 110	$ 343	$ 595	$ 1,317

Portfolio Turnover: The Fund pays transaction costs, such as commissions, 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 annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 170% of the average value of its portfolio.

Principal investment strategies

The Fund pursues its investment objective by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in bonds. For purposes of this 80% policy, the term bonds refers to a variety of fixed-income securities and instruments, and includes, but is not limited to, such investments as government notes and bonds, corporate bonds, convertible securities, commercial paper, commercial and residential mortgage-backed securities, asset-backed securities, collateralized loan obligations, fixed rate notes, floating rate securities, and derivatives such as forwards, swap agreements, futures contracts, and options that provide exposure to various fixed-income instruments (“Fixed-Income Instruments”). The Fund may invest a significant portion of its assets in certain types of Fixed-Income Instruments, including mortgage-backed securities. In pursuing its investment objective, the Fund will have exposure to investments that are economically tied to a number of countries throughout the world.

The Fund employs an “absolute return” strategy, which means that the Fund benchmarks itself to an index of cash instruments, rather than a fixed-income index. In pursuing this strategy, the Fund seeks to achieve positive returns that exceed its benchmark index in a variety of market environments. The Fund seeks value across sectors and geographies using a wide range of instruments to capitalize on investment opportunities to maximize current income, while at the same time seeking to provide low volatility. The Fund seeks to take advantage of market mispricings and dislocations caused by structural inefficiencies in the fixed-income market. For example, the portfolio managers may favor investments in smaller countries or regions that tend to be underrepresented in fixed-income indices that are more heavily focused on the United States or other larger regions globally.

The Fund’s average portfolio duration may range from negative 2 years to plus 4 years. As of June 30, 2019, the Fund’s average portfolio duration was 1.67 years. While the Fund primarily invests in investment-grade debt securities, it may invest up to 25% of its assets in high-yield/high-risk bonds, also known as “junk” bonds. The Fund may invest in securities denominated in foreign currencies and in U.S. dollar-denominated securities of foreign issuers. Due to the nature of the securities in which the Fund invests, it may have relatively high portfolio turnover compared to other funds.

The Fund may invest in foreign debt securities, including investments in emerging markets. At times, the Fund may invest a substantial amount of its assets in foreign debt issuers located in a single region. The Fund will normally limit emerging markets investments to 25% of its net assets, measured at the time of purchase. The Fund will normally limit its foreign currency exchange exposure to 15% of its total assets. The Fund may limit its foreign currency exchange exposure by hedging through the use of forward contracts, cross-currency swaps, currency futures, and options. The Fund may invest in cash or cash equivalents such as short-term government bonds, commercial paper, repurchase agreements, reverse repurchase agreements, and other short-duration fixed-income securities. The Fund may also invest in securities that cannot be offered

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for public resale unless registered under the applicable securities laws or that have a contractual restriction that prohibits or limits their resale (these are known as “restricted securities”).

The Fund may invest in derivatives, which are instruments that have a value derived from, or directly linked to, an underlying asset, such as equity securities, fixed-income securities, commodities, currencies, interest rates, or market indices. In particular, the Fund may utilize swap agreements, futures and options for various investment purposes, such as to manage or hedge portfolio risk, enhance return, or manage duration.

The Fund may engage in short sales of fixed-income securities. The Fund may implement short positions through derivatives such as options, futures, or swaps.

The Fund may lend portfolio securities on a short-term or long-term basis, in an amount equal to up to one-third of its total assets as determined at the time of the loan origination.

Principal investment risks

Although the Fund may be less volatile than funds that invest most of their assets in common stocks, the Fund’s returns and yields will vary, and you could lose money.

Fixed-Income Securities Risk.  The Fund invests in a variety of fixed-income securities. Typically, the values of fixed-income securities change inversely with prevailing interest rates. Therefore, a fundamental risk of fixed-income securities is interest rate risk, which is the risk that the value of such securities will generally decline as prevailing interest rates rise, which may cause the Fund’s net asset value to likewise decrease. For example, while securities with longer maturities and durations tend to produce higher yields, they also tend to be more sensitive to changes in prevailing interest rates and are therefore more volatile than shorter-term securities and are subject to greater market fluctuations as a result of changes in interest rates. Investments in fixed-income securities with very low or negative interest rates may diminish the Fund’s yield and performance. Recent and potential future changes in government monetary policy may also affect the level of interest rates. These changes could cause the Fund’s net asset value to fluctuate or make it more difficult for the Fund to accurately value its securities. These changes or others also could cause the Fund to face increased shareholder redemptions, which may lead to increased portfolio turnover and transaction costs, or could force the Fund to liquidate investments at disadvantageous times or prices, therefore adversely affecting the Fund as well as the value of your investment. The amount of assets deemed illiquid remaining within the Fund may also increase, making it more difficult to meet shareholder redemptions and further adversely affecting the value of the Fund. How specific fixed-income securities may react to changes in interest rates will depend on the specific characteristics of each security. Fixed-income securities are also subject to credit risk, prepayment risk, valuation risk, extension risk, and liquidity risk. Credit risk is the risk that the credit strength of an issuer of a fixed-income security will weaken and/or that the issuer will be unable to make timely principal and interest payments and that the security may go into default. Prepayment risk is the risk that during periods of falling interest rates, certain fixed-income securities with higher interest rates, such as mortgage- and asset-backed securities, may be prepaid by their issuers thereby reducing the amount of interest payments. Valuation risk is the risk that one or more of the fixed-income securities in which the Fund invests are priced differently than the value realized upon such security’s sale. In times of market instability, valuation may be more difficult. Extension risk is the risk that borrowers may pay off their debt obligations more slowly in times of rising interest rates, which will lengthen the duration of the portfolio. Liquidity risk is the risk that fixed-income securities may be difficult or impossible to sell at the time that the portfolio managers would like or at the price the portfolio managers believe the security is currently worth.

High-Yield/High-Risk Bond Risk.  High-yield/high-risk bonds are considered speculative and may be more sensitive than other types of bonds to economic changes, political changes, or adverse developments specific to the company that issued the bond, which may adversely affect their value.

Mortgage- and Asset-Backed Securities Risk.  Mortgage- and asset-backed securities represent interests in “pools” of commercial or residential mortgages or other assets, including consumer loans or receivables. Mortgage- and asset-backed securities tend to be more sensitive to changes in interest rates than other types of debt securities. Investments in mortgage-and asset-backed securities are subject to both extension risk, where borrowers pay off their debt obligations more slowly in times of rising interest rates, and prepayment risk, where borrowers pay off their debt obligations sooner than expected in times of declining interest rates. These risks may reduce the Fund’s returns. In addition, investments in mortgage- and asset-backed securities, including those comprised of subprime mortgages, may be subject to a higher degree of credit risk, valuation risk, and liquidity risk than various other types of fixed-income securities.

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Foreign Exposure Risk.  The Fund normally has significant exposure to foreign markets as a result of its investments in foreign securities, including investments in emerging markets, which can be more volatile than the U.S. markets. As a result, its returns and net asset value may be affected to a large degree by fluctuations in currency exchange rates or political or economic conditions in a particular country. In some foreign markets, there may not be protection against failure by other parties to complete transactions. It may not be possible for the Fund to repatriate capital, dividends, interest, and other income from a particular country or governmental entity. In addition, a market swing in one or more countries or regions where the Fund has invested a significant amount of its assets may have a greater effect on the Fund’s performance than it would in a more geographically diversified portfolio. To the extent the Fund invests in foreign debt securities, such investments are sensitive to changes in interest rates. Additionally, investments in securities of foreign governments involve the risk that a foreign government may not be willing or able to pay interest or repay principal when due. The Fund’s investments may be denominated in foreign currencies and therefore, changes in the value of a country’s currency compared to the U.S. dollar may affect the value of the Fund’s investments. Some of the risks of investing directly in foreign securities may be reduced when the Fund invests indirectly in such securities through various other investment vehicles including derivatives, which also involve other risks. The Fund’s investments in emerging market countries may involve risks greater than, or in addition to, the risks of investing in more developed countries.

Geographic Concentration Risk.  To the extent the Fund invests a substantial amount of its assets in issuers located in a single country or region, the economic, political, social, regulatory, or other developments or conditions within such country or region will generally have a greater effect on the Fund than they would on a more geographically diversified fund, which may result in greater losses and volatility. Adverse developments in certain regions could also adversely affect securities of other countries whose economies appear to be unrelated and could have a negative impact on the Fund’s performance.

Emerging Markets Risk.  The risks of foreign investing are heightened when investing in emerging markets. Emerging markets securities involve a number of additional risks, which may result from less government supervision and regulation of business and industry practices (including the potential lack of strict finance and accounting controls and standards), stock exchanges, brokers, and listed companies, making these investments potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Fund’s investments. In addition, the Fund’s investments may be denominated in foreign currencies and therefore, changes in the value of a country’s currency compared to the U.S. dollar may affect the value of the Fund’s investments. To the extent that the Fund invests a significant portion of its assets in the securities of emerging markets issuers in or companies of a single country or region, it is more likely to be impacted by events or conditions affecting that country or region, which could have a negative impact on the Fund’s performance. Some of the risks of investing directly in emerging market securities may be reduced when the Fund invests indirectly in such securities through various other investment vehicles including derivatives, as noted in the Fund’s Summary Prospectus, but such investments also involve other risks. As of June 30, 2019, approximately 13.2% of the Fund’s investments were in emerging markets (i.e., countries included in the MSCI Emerging Markets Index^sm).

Derivatives Risk.  Derivatives, such as swaps, futures, forwards, and options, can be highly volatile and involve risks similar to those of the underlying referenced securities or assets, such as risks related to interest rates, market, credit, valuation, and liquidity, among others. There are also additional risks. Gains or losses from a derivative investment can be substantially greater than the derivative’s original cost, and can therefore involve leverage. Leverage may cause the Fund to be more volatile than if it had not used leverage. Derivatives can be complex instruments and may involve analysis that differs from that required for other investment types used by the Fund. If the value of a derivative does not correlate well with the particular market or other asset class to which the derivative is intended to provide exposure, the derivative may not produce the anticipated result. Derivatives can also reduce the opportunity for gain or result in losses by offsetting positive returns in other investments. Derivatives can be less liquid than other types of investments and entail the risk that the counterparty will default on its payment obligations. If the counterparty to a derivative transaction defaults, the Fund would risk the loss of the net amount of the payments that it contractually is entitled to receive. To the extent the Fund enters into short derivative positions, the Fund may be exposed to risks similar to those associated with short sales, including the risk that the Fund’s losses are theoretically unlimited. Derivatives may be difficult to value, are susceptible to liquidity risk, and entail the risk that a party will default on its obligations to the Fund. If there is a default by the other party to such a transaction, the Fund normally will have contractual remedies pursuant to the agreements related to the transaction. Swap agreements also bear the

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risk that the Fund will not be able to meet its obligation to the counterparty. The Fund’s investments in interest rate futures in particular entail the risk that the Fund’s portfolio managers’ prediction of the direction of interest rates is wrong, and the Fund could incur a loss. If the Fund invests a significant portion of its assets in derivatives, its investment performance could be dependent on securities not directly owned by the Fund. The Fund may use derivatives for hedging purposes. Hedging with derivatives may increase expenses, and there is no guarantee that a hedging strategy will work. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains or cause losses if the market moves in a manner different from that anticipated by the portfolio managers or if the cost of the derivative outweighs the benefit of the hedge.

Sovereign Debt Risk.  The Fund may invest in U.S. and non-U.S. government debt securities (“sovereign debt”). Some investments in sovereign debt, such as U.S. sovereign debt, are considered low risk. However, investments in sovereign debt, especially the debt of less developed countries, can involve a high degree of risk, including the risk that the governmental entity that controls the repayment of sovereign debt may not be willing or able to repay the principal and/or to pay the interest on its sovereign debt in a timely manner. A sovereign debtor’s willingness or ability to satisfy its debt obligation may be affected by various factors including, but not limited to, its cash flow situation, the extent of its foreign currency reserves, the availability of foreign exchange when a payment is due, and the relative size of its debt position in relation to its economy as a whole. In the event of default, there may be limited or no legal remedies for collecting sovereign debt and there may be no bankruptcy proceedings through which the Fund may collect all or part of the sovereign debt that a governmental entity has not repaid. In addition, to the extent the Fund invests in non-U.S. sovereign debt, it may be subject to currency risk.

Loan Risk.  The Fund may invest in a variety of loans. Bank loans are obligations of companies or other entities entered into in connection with recapitalizations, acquisitions, and refinancings. The Fund’s investments in bank loans are generally acquired as a participation interest in, or assignment of, loans originated by a lender or other financial institution. These investments may include institutionally-traded floating and fixed-rate debt securities. The bank loans underlying these securities often involve borrowers with low credit ratings whose financial conditions are troubled or uncertain, including companies that are highly leveraged or in bankruptcy proceedings. Participation interests and assignments involve credit, interest rate, and liquidity risk. Bridge loans involve certain risks in addition to those associated with bank loans including the risk that the borrower may be unable to locate permanent financing to replace the bridge loan, which may impair the borrower’s perceived creditworthiness. Debtor-in-possession (“DIP”) loans are subject to the risk that the entity will not emerge from bankruptcy and will be forced to liquidate its assets. Mezzanine loans generally are rated below investment grade, and frequently are unrated. Investment in mezzanine loans is a specialized practice that depends more heavily on independent credit analysis than investments in other fixed-income securities.

Floating Rate Obligations Risk.  There may be a number of intermediate participants in floating rate obligation transactions and loan agreements that have specific rights and obligations, and terms and conditions. Unexpected changes in the interest rates on floating rate obligations could result in losses to the Fund. In addition, the secondary market on which floating rate obligations are traded may be less liquid than the market for investment grade securities or other types of income-producing securities, which may have an adverse impact on their market price. There is also a potential that there is no active market to trade floating rate obligations and that there may be restrictions on their transfer. As a result, the Fund may be unable to sell assignments or participations at the desired time or may be able to sell only at a price less than fair market value.

Liquidity Risk.  The Fund may invest in securities or instruments that do not trade actively or in large volumes, and may make investments that are less liquid than other investments. Also, the Fund may make investments that may become less liquid in response to market developments or adverse investor perceptions. Investments that are illiquid or that trade in lower volumes may be more difficult to value. When there is no willing buyer and investments cannot be readily sold at the desired time or price, the Fund may have to accept a lower price or may not be able to sell the security or instrument at all. Investments in foreign securities, particularly those of issuers located in emerging market countries, tend to have greater exposure to liquidity risk than domestic securities. In unusual market conditions, even normally liquid securities may be affected by a degree of liquidity risk (i.e., if the number and capacity of traditional market participants is reduced). An inability to sell one or more portfolio positions can adversely affect the Fund’s value or prevent the Fund from being able to take advantage of other investment opportunities.

LIBOR Replacement Risk.  The elimination of London Inter-Bank Offered Rate (“LIBOR”) may adversely affect the interest rates on, and value of, certain Fund investments for which the value is tied to LIBOR. The U.K. Financial Conduct Authority has announced that it intends to stop compelling or inducing banks to submit LIBOR rates after 2021. However, it remains unclear if LIBOR will continue to exist in its current, or a modified, form. Alternatives to LIBOR are established or in development in most major currencies including the Secured Overnight Financing Rate (SOFR), that is intended to replace

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U.S. dollar LIBOR. Markets are slowly developing in response to these new rates. Questions around liquidity impacted by these rates, and how to appropriately adjust these rates at the time of transition, remain a concern for the Fund. The effect of any changes to, or discontinuation of, LIBOR on the Fund will vary, and it is difficult to predict the full impact of the transition away from LIBOR on the Fund until new reference rates and fallbacks for both legacy and new products, instruments and contracts are commercially accepted.

Currency Risk.  As long as the Fund holds a foreign security, its value will be affected by the value of the local currency relative to the U.S. dollar. When the Fund sells a foreign currency denominated security, its value may be worth less in U.S. dollars even if the security increases in value in its home country. U.S. dollar-denominated securities of foreign issuers may also be affected by currency risk, as the value of these securities may also be affected by changes in the issuer’s local currency.

Rule 144A Securities Risk.  The Fund may invest in Rule 144A securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but which may be resold to certain institutional investors. Such securities may be determined to be liquid in accordance with the Fund’s applicable policies and procedures and Rule 22e-4. However, an insufficient number of qualified institutional buyers interested in purchasing Rule 144A securities at a particular time could affect negatively the Fund’s ability to dispose of such securities promptly or at expected prices. Accordingly, the Fund’s investment in Rule 144A securities may subject the Fund to enhanced liquidity risk and potentially increase the Fund’s exposure to illiquid investments if eligible buyers become uninterested in buying Rule 144A securities at a particular time.

Short Sales Risk.  Entering into short sales can involve the loss of more money than the actual cost of the investment, and the risk of loss if the third party to the short sale does not honor its contract terms.

Reverse Repurchase Agreement Risk.  In a reverse repurchase agreement, there is a risk that the other party to the agreement fails to return the securities in a timely manner or at all. The Fund could lose money if it is unable to recover the securities and/or the value of the collateral held by the Fund is less than the value of such securities.

Management Risk.  The Fund is an actively managed investment portfolio and is therefore subject to the risk that the investment strategies employed for the Fund may fail to produce the intended results. Although the Fund seeks to provide long-term positive returns, market conditions or implementation of the Fund’s investment process may result in losses, and the Fund will not meet its investment objective. As such, there can be no assurance of positive “absolute” returns.

Portfolio Turnover Risk.  Increased portfolio turnover may result in higher costs, which may have a negative effect on the Fund’s performance. In addition, higher portfolio turnover may result in the acceleration of capital gains and the recognition of greater levels of short-term capital gains, which are taxed at ordinary federal income tax rates when distributed to shareholders.

Securities Lending Risk.  The Fund may seek to earn additional income through lending its securities to certain qualified broker-dealers and institutions. There is the risk that when portfolio securities are lent, the securities may not be returned on a timely basis, and the Fund may experience delays and costs in recovering the security or gaining access to the collateral provided to the Fund to collateralize the loan. If the Fund is unable to recover a security on loan, the Fund may use the collateral to purchase replacement securities in the market. There is a risk that the value of the collateral could decrease below the cost of the replacement security by the time the replacement investment is made, resulting in a loss to the Fund.

An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

The following information provides some indication of the risks of investing in the Fund by showing how the Fund’s performance has varied over time. The bar chart depicts the change in performance from year to year during the periods indicated. The table compares the Fund’s average annual returns for the periods indicated to broad-based securities market indices. All figures assume reinvestment of dividends and distributions. For certain periods, the Fund’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

The Fund’s past performance (before and after taxes) does not necessarily indicate how it will perform in the future.Updated performance information is available at janushenderson.com/allfunds or by calling 1-800-525-3713.

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Annual Total Returns for Class D Shares (calendar year-end)

Best Quarter: 4th Quarter 2018 2.20% Worst Quarter: 2nd Quarter 2018 – 5.70%

The Fund’s year-to-date return as of the calendar quarter ended September 30, 2019 was 2.79%.

Average Annual Total Returns (periods ended 12/31/18)
	1 Year	Since Inception (5/27/14)
Class D Shares
Return Before Taxes	– 4.04%	0.17%
Return After Taxes on Distributions	– 5.18%	– 0.81%
Return After Taxes on Distributions and Sale of Fund Shares(1)	– 2.37%	– 0.29%
FTSE 3-Month US Treasury Bill Index (reflects no deduction for expenses, fees, or taxes)	1.86%	0.71%
3-Month USD LIBOR (reflects no deduction for expenses, fees, or taxes)	2.08%	0.91%

(1)  If the Fund incurs a loss, which generates a tax benefit, the Return After Taxes on Distributions and Sale of Fund Shares may exceed the Fund’s other return figures.

Effective June 28, 2019, the Fund’s primary benchmark index changed from the 3-Month USD LIBOR to the FTSE 3-Month US Treasury Bill Index (the “T-Bill Index”). Janus Capital believes that the T-Bill Index represents a more relevant cash benchmark for the Fund. In addition, regulators have signaled intent to phase out LIBOR as a key market interest rate by the end of 2021. The indices are described below.

• The T-Bill Index is an unmanaged index designed to represent the average of Treasury bill rates for each of the prior 3 months, adjusted to a bond equivalent basis.

• The 3-Month USD LIBOR is a daily reference rate based on the interest rates at which banks offer to lend unsecured funds to other banks in the London wholesale money market (or interbank market).

After-tax returns are calculated using the historically highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on your individual tax situation and may differ from those shown in the preceding table. The after-tax return information shown above does not apply to Fund shares held through a tax-advantaged account, such as a 401(k) plan or an IRA.

Management

Investment Adviser:  Janus Capital Management LLC

Portfolio Managers: Nick Maroutsos is Executive Vice President and Co-Portfolio Manager of the Fund, which he has managed or co-managed since February 2019. Jason England is Executive Vice President and Co-Portfolio Manager of the Fund, which he has co-managed since June 2019.

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Purchase and sale of Fund shares

Minimum Investment Requirements
To open a new regular Fund account	$2,500
To open a new regular Fund account with an automatic investment program of $50 per month	$ 100
To open a new UGMA/UTMA account, Coverdell Education Savings Account, or a retirement Fund account
• without an automatic investment program	$1,000
• with an automatic investment program of $50 per month	$ 100
To add to any existing type of Fund account without an automatic investment program	$ 50

You may generally purchase, exchange, or redeem Fund Shares on any business day by written request, wire transfer, telephone, and in most cases, online at janushenderson.com/individual. You may conduct transactions by mail (Janus Henderson, P.O. Box 219109, Kansas City, MO 64121-9109), or by telephone at 1-800-525-3713. Purchase, exchange, or redemption requests must be received in good order by the Fund or its agents prior to the close of the regular trading session of the New York Stock Exchange in order to receive that day’s net asset value. For additional information, refer to “To Open an Account or Buy Shares,” “To Exchange Shares,” and/or “To Sell Shares” in the Prospectus.

Tax information

The Fund’s distributions are taxable, and will be taxed as ordinary income or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account (in which case you may be taxed upon withdrawal of your investment from such account).

Payments to broker-dealers and other financial intermediaries

With respect to share classes not offered in this Prospectus, the Fund and its related companies pay select broker-dealer firms or other financial intermediaries for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing a broker-dealer or other intermediary or a salesperson to recommend the Fund over another investment or to recommend one share class over another.

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