nv1aza

Average Daily

Contractual

Net Assets

Management Fee (%)

Fund Name

of the Fund

(annual rate)

Janus Small Cap Growth Alpha ETF

All Asset Levels

As filed with the U.S. Securities and Exchange Commission on February 18, 2016

Securities Act File No. 333-207814
Investment Company Act File No. 811-23112

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A


REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933		x

Pre-Effective Amendment No. 1		x

Post-Effective Amendment No.		o

and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940		x

Amendment No. 1		x

JANUS DETROIT STREET TRUST

(Exact Name of Registrant as Specified in Charter)

151 Detroit Street, Denver, Colorado 80206-4805
(Address of Principal Executive Offices) (Number, Street, City, State, Zip Code)

Registrant’s Telephone Number, including Area Code: 303-333-3863

Stephanie Grauerholz
151 Detroit Street
Denver, Colorado 80206-4805

(Name and Address of Agent for Service)

With Copies to:

Eric S. Purple
K&L Gates LLP
1601 K Street N.W.
Washington, D.C. 20006

Approximate Date of Proposed Public Offering: As soon as practicable after the effective date of this Registration Statement.

The Registrant hereby amends this Registration Statement under the Securities Act of 1933 on such date or dates as may be necessary to delay its effective date until Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with the provisions of Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to Section 8(a), shall determine.

If appropriate, check the following box:

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

The information in this Prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This Prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

6 [ , 2016]

Subject to Completion

Preliminary Prospectus Dated February 18, 2016


		Ticker
Janus Small Cap Growth Alpha ETF		JSML
Principal U.S. Listing Exchange: NASDAQ Stock Market, Inc.

Janus Detroit Street Trust

Prospectus

The Securities and Exchange Commission has not approved or disapproved of these securities or passed on the accuracy or adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Fund summary

Janus Small Cap Growth Alpha ETF


Ticker:		JSML

INVESTMENT OBJECTIVE

Janus Small Cap Growth Alpha ETF seeks investment results that correspond generally, before fees and expenses, to the performance of its underlying index, the Janus Small Cap Growth Alpha Index (the “Underlying Index”).

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. Investors may pay brokerage commissions on their purchases and sales of Fund shares, which are not reflected in the table or in the example below.


ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Management Fees							0.50%
Other Expenses⁽¹⁾							0.00%
Total Annual Fund Operating Expenses							0.50%


(1)	Other Expenses are based on the estimated expenses that the Fund expects to incur.

EXAMPLE:

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:


1 Year		3 Years
$	51	$	160

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. Because the Fund was not in operation during the most recent fiscal year, no portfolio turnover information is available.

PRINCIPAL INVESTMENT STRATEGIES

The Fund pursues its investment objective by normally investing at least 80% of its net assets (plus any borrowings for investment purposes) in the securities that comprise the Janus Small Cap Growth Alpha Index (“Underlying Index”).

The Underlying Index, Janus Small Cap Growth Alpha Index, is composed of common stocks of small-sized companies that are selected by the index provider, Janus Index & Calculation Services LLC (“Janus Index Services” or the “Index Provider”), from those companies included in the Solactive Small Cap Index, a universe of 2,000 small-sized capitalization stocks. The Underlying Index is designed to select small-sized capitalization stocks that are poised for “smart growth” by evaluating each company’s performance in three critical areas: growth, profitability, and capital efficiency. The Index Provider scores such stocks based on fundamental measures of their growth, profitability, and capital efficiency, and selects the top 10% of such eligible stocks scoring the highest using a proprietary quantitative methodology. To arrive at the top 10%, for each security in the stated universe, the quantitative methodology assigns a score in each of 10 different fundamental factors, relative to other eligible securities. The fundamental factors include measures that Janus Capital believes are tied to a stock’s outperformance relative to other small cap stocks, and indicate a company’s performance with respect to growth (such as the revenue growth rate over 2- 5- and 8- year periods), profitability (such as margin expansion, profit margin and earnings per share over time) and capital efficiency (such as returns on invested capital). The scores for each factor are then added together, with equal

2 ï Janus Small Cap Growth Alpha ETF

weighting, to arrive at an overall score. The stocks with the highest 10% of scores are then weighted within the Underlying Index according to their market capitalization. Finally, the stocks are sector-weighted to reflect the sector allocation weight of Janus Venture Fund, based on its most recent publicly available holdings. A stock may not represent more than 3% of the Underlying Index. The Underlying Index, Janus Small Cap Growth Alpha Index, seeks risk adjusted outperformance relative to a market capitalization weighted universe of small-sized capitalization growth stocks. Market capitalizations within the Underlying Index will vary, but as of January 29, 2016, they ranged from approximately $53 million to $5.4 billion. The Underlying Index is rebalanced on a quarterly basis based on the methodology described above.

The Fund uses a “passive,” index-based approach in seeking performance that corresponds to the performance of the Underlying Index. The Fund generally will use a replication methodology, meaning it will invest in the securities composing the Underlying Index, Janus Small Cap Growth Alpha Index, in proportion to the weightings in the Underlying Index. However, the Fund may utilize a sampling methodology under various circumstances in which it may not be possible or practicable to purchase all of the securities in the Underlying Index. Janus Capital expects that over time, if the Fund has sufficient assets, the correlation between the Fund’s performance, before fees and expenses, and that of the Underlying Index will be 95% or better. A figure of 100% would indicate perfect correlation.

The Fund may also invest in investments that are not included in the Underlying Index, but which Janus Capital believes will help the Fund track its Underlying Index. Such investments include stocks, shares of other investment companies, cash and cash equivalents, including money market funds.

To the extent the Underlying Index concentrates (i.e., holds 25% or more of its total assets) in the securities of a particular industry or group of industries, the Fund will concentrate its investments to approximately the same extent as its Underlying Index. As of January 29, 2016, the Underlying Index did not concentrate in a particular industry or group of industries. The Fund’s Underlying Index is rebalanced quarterly. For more recent information, see the Fund’s daily portfolio holdings posted on the ETF portion of the Janus website.

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

The Fund’s returns and yields will vary, and you could lose money. The principal risks and special considerations associated with investing in the Fund are set forth below.

Market Risk. The value of the Fund’s portfolio may decrease if the value of an individual company or security, or multiple companies or securities, in the portfolio decreases. Further, regardless of how well individual companies or securities perform, the value of the Fund’s portfolio could also decrease if there are deteriorating economic or market conditions. It is important to understand that the value of your investment may fall, sometimes sharply, in response to changes in the market, and you could lose money. Market risk may affect a single issuer, industry, economic sector, or the market as a whole. The Underlying Index has exposure to the small-sized capitalization sector of the stock market, and therefore at times the Fund may underperform the overall stock market.

Equity Investing Risk. The Fund’s investment in the securities composing the Underlying Index involves risks of investing in a portfolio of equity securities, such as market fluctuations, changes in interest rates and perceived trends in stock prices.

Small-Sized Companies Risk. The Fund’s investments in securities issued by small-sized companies, which can include smaller, start-up companies offering emerging products or services, may involve greater risks than are customarily associated with larger, more established companies. Securities issued by small-sized companies tend to be more volatile and somewhat more speculative than securities issued by larger or more established companies and may underperform as compared to the securities of larger companies.

Growth Securities Risk. Securities of companies perceived to be “growth” companies may be more volatile than other stocks and may involve special risks. If the perception of a company’s growth potential, based on the portfolio managers’ quantitative methodology, is not realized, the securities purchased may not perform as expected, reducing the Fund’s returns. In addition, because different types of stocks tend to shift in and out of favor depending on market and economic conditions, “growth” stocks may perform differently from the market as a whole and other types of securities.

3 ï Janus Small Cap Growth Alpha ETF

Investment Style Risk. Returns from small-sized capitalization stocks may trail returns from the overall stock market. Small-cap stocks may go through cycles of doing better or worse than other segments of the stock market or the stock market in general. These cycles may continue for extended periods of time.

Concentration Risk. The Fund’s assets will generally be concentrated in an industry or group of industries to the extent that the Fund’s Underlying Index concentrates in a particular industry or group of industries. To the extent the Fund invests a substantial portion of its assets in an industry or group of industries, market or economic factors impacting that industry or group of industries could have a significant effect on the value of the Fund’s investments. Companies in the same or similar industries may share common characteristics and are more likely to react similarly to industry-specific market or economic developments. For example, information technology companies often progress at an accelerated rate, and these companies may be subject to short product cycles and aggressive pricing, which may increase their volatility. Additionally, the Fund’s performance may be more volatile when the Fund’s investments are less diversified across industries. The Fund’s assets will not be concentrated if the Underlying Index does not concentrate in a particular industry or group of industries.

Early Close/Trading Halt Risk. An exchange or market may close or issue trading halts on specific securities, or the ability to buy or sell certain securities or financial instruments may be restricted, which may result in the Fund being unable to buy or sell certain securities or financial instruments. In such circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments and/or may incur substantial trading losses.

Index Tracking Risk. The Fund’s return may not match or achieve a high degree of correlation with the return of the Underlying Index. To the extent the Fund utilizes a sampling approach, it may experience tracking error to a greater extent than if the Fund sought to replicate the Underlying Index. In addition, the Fund may hold fewer than the total number of securities in the Underlying Index. As a result, the Fund may hold securities not included in the Underlying Index.

Management Risk. The Fund is subject to management risk. This is the risk that Janus Capital’s security selection process, which is subject to a number of constraints, may not produce the intended results.

Methodology and Model Risk. Neither the Fund nor Janus Capital can offer assurances that tracking the Underlying Index will maximize returns or minimize risk, or be appropriate for every investor seeking a particular risk profile. Underlying Index risks include, but are not limited to, the risk that the factors used to determine the components of the Underlying Index, as applied by the Index Provider in accordance with the Underlying Index methodology, might not select securities that individually, or in the aggregate, outperform the broader small-sized capitalization universe. In addition, the Underlying Index was designed based on historically relevant fundamental factors and may not provide risk-adjusted outperformance in the future.

Passive Investment Risk. The Fund is not actively managed and therefore the Fund might not sell shares of a security due to current or projected underperformance of a security, industry or sector, unless that security is removed from the Underlying Index or the selling of shares is otherwise required upon a rebalancing of the Underlying Index.

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.

Trading Issues Risk. Although Fund shares are listed for trading on the NASDAQ Stock Market, Inc. (“NASDAQ”), there can be no assurance that an active trading market for such shares will develop or be maintained. Trading in Fund shares may be halted due to market conditions or for reasons that, in the view of the NASDAQ, make trading in shares inadvisable. In addition, trading in shares is subject to trading halts caused by extraordinary market volatility pursuant to the NASDAQ “circuit breaker” rules. There can be no assurance that the requirements of the NASDAQ necessary to maintain the listing of the Fund will continue to be met or will remain unchanged or that the shares will trade with any volume, or at all.

4 ï Janus Small Cap Growth Alpha ETF

shares will trade below, at or above the Fund’s NAV. If an investor purchases shares at a time when the market price is at a premium to the NAV of the shares or sells at a time when the market price is at a discount to the NAV of the shares, then the investor may sustain losses.

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 Fund does not have a full calendar year of operations. Performance information for certain periods will be included in the Fund’s first annual and/or semiannual report and is available at janus.com/etfs or by calling 1-877-335-2687. When provided, the information will provide some indication of the risks of investing in the Fund by showing how the Fund’s average annual returns compare with a broad measure of market performance. Past performance does not necessarily indicate how the Fund will perform in the future.

MANAGEMENT

Investment Adviser: Janus Capital Management LLC

Portfolio Managers: Benjamin Wang, CFA, is Co-Portfolio Manager of the Fund, which he has co-managed since February 2016. Scott M. Weiner, DPhil, is Co-Portfolio Manager of the Fund, which he has co-managed since February 2016.

PURCHASE AND SALE OF FUND SHARES

Unlike shares of traditional mutual funds, shares of the Fund are not individually redeemable and may only be purchased or redeemed directly from the Fund at net asset value (“NAV”) in large increments called “Creation Units” (50,000 or more shares per Creation Unit) through certain participants, known as “Authorized Participants.” The Fund will issue or redeem Creation Units in exchange for portfolio securities included in the Fund’s Underlying Index and/or cash. Except when aggregated in Creation Units, Fund shares are not redeemable securities of the Fund.

Shares of the Fund are listed and trade on the NASDAQ, and individual investors can purchase or sell shares in much smaller increments and for cash in the secondary market through a broker. These transactions, which do not involve the Fund, are made at market prices that may vary throughout the day and differ from the Fund’s net asset value. As a result, you may pay more than net asset value (at a premium) when you purchase shares, and receive less than net asset value (at a discount) when you sell shares, in the secondary market.

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-deferred 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). A sale of Fund shares may result in a capital gain or loss.

PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund, Janus Capital and/or its affiliates may pay broker-dealers or intermediaries for the sale and/or maintenance of Fund shares and 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.

5 ï Janus Small Cap Growth Alpha ETF

Additional information about the Fund

FEES AND EXPENSES

Please refer to the following important information when reviewing the “Fees and Expenses of the Fund” table in the Fund Summary of the Prospectus. The fees and expenses shown reflect estimated annualized expenses that the shares expect to incur.


•	“Annual Fund Operating Expenses” are paid out of the Fund’s assets. You do not pay these fees directly but, as the Example in the Fund Summary shows, these costs are borne indirectly by all shareholders.

•	The “Management Fee” is the rate paid by the Fund to Janus Capital for providing certain services. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•	“Other Expenses”


	○	include taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, securities lending expenses, and extraordinary expenses (such as litigation and indemnification expenses).


	○	include acquired fund fees and expenses, which are indirect expenses the Fund may incur as a result of investing in shares of an underlying fund. “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. Such amounts are currently estimated to be less than 0.01%.


•	All expenses in the Fund’s “Fees and Expenses of the Fund” table are shown without the effect of expense offset arrangements. Pursuant to such arrangements, credits realized as a result of uninvested cash balances are used to reduce custodian and transfer agent expenses.

ADDITIONAL INVESTMENT STRATEGIES AND GENERAL PORTFOLIO POLICIES

The Fund’s Board of Trustees (“Trustees”) may change the Fund’s investment objective or non-fundamental principal investment strategies without a shareholder vote. The Fund will notify you in writing at least 60 days or as soon as reasonably practicable before making any such change it considers material. In addition, the Fund will provide shareholders with at least 60 days’ notice prior to changing the 80% investment policy. If there is a material change to the Fund’s objective or principal investment strategies, you should consider whether the Fund remains an appropriate investment for you. There is no guarantee that the Fund will achieve its investment objective.

The Fund’s portfolio holdings are disclosed on its website daily after the close of trading on the exchange and prior to the opening of trading on the exchange the following day. A description of the Fund’s policies and procedures with respect to the disclosure of the Fund’s portfolio holdings is available in the Fund’s statement of additional information. Information about the premiums and discounts at which the Fund’s shares have traded will be available at janus.com/etfs.

Unless otherwise stated, the following additional investment strategies and general policies apply to the Fund and provide further information including, but not limited to, the types of securities the Fund may invest in when implementing its investment objective. Some of these strategies and policies may be part of a principal strategy. Other strategies and policies may be utilized to a lesser extent. Except for the Fund’s policies with respect to investments in illiquid securities and borrowing, the percentage limitations included in these policies and elsewhere in this Prospectus and/or the SAI normally apply only at the time of purchase of a security. So, for example, if the Fund exceeds a limit as a result of market fluctuations or the sale of other securities, it will not be required to dispose of any securities.

Real Estate-Related Securities

Although not considered a principal investment strategy, the Fund may invest in equity securities of real estate-related companies to the extent such securities are included in the Underlying Index. Such companies may include those in the real estate industry or real estate-related industries. These securities may include common stocks, preferred stocks, and other equity securities, such as mortgage-backed securities, real estate-backed securities, securities of real estate investment trusts (“REITs”) and similar REIT-like entities. A REIT is a trust that invests in real estate-related projects, such as properties, mortgage loans, and construction loans. REITs are generally categorized as equity, mortgage, or hybrid REITs. A REIT may be listed on an exchange or traded over-the-counter.

6 ï Janus Detroit Street Trust

Securities Lending

Although not considered a principal investment strategy, the Fund may seek to earn additional income through lending its securities to certain qualified broker-dealers and institutions on a short-term or long-term basis. 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. When the Fund lends its securities, it receives collateral (including cash collateral), at least equal to the value of securities loaned. The Fund may earn income by investing this collateral in one or more affiliated or non-affiliated cash management vehicles. It is also possible that, due to a decline in the value of a cash management vehicle in which collateral is invested, the Fund may lose money. There is also 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. To the extent Janus Capital manages the cash collateral in an affiliated cash management vehicle, it will receive an investment advisory fee for managing such assets.

Non-Index Investments

Although not considered a principal investment strategy, the Fund may invest in investments that are not included in the Underlying Index, but which Janus Capital believes will help the Fund track its Underlying Index. Such investments include stocks, shares of other investment companies, cash and cash equivalents, including money market funds. There may be instances where a stock is removed from the Underlying Index but Janus Capital may elect to hold it for tax-related purposes, or where the Fund receives non-Underlying Index stocks in a corporate action and does not sell the stocks until the next rebalance date. Janus Capital may also choose to hold non-Underlying Index stocks due to an optimization methodology to more efficiently track the Underlying Index. Use of an optimization methodology would entail the use of a program or model designed to identify securities that are not included in the Underlying Index, but would be expected to behave similarly to securities that are in the Underlying Index.

RISKS OF THE FUND

The value of your investment will vary over time, sometimes significantly, and you may lose money by investing in the Fund. The Fund invests substantially all of its assets in small-sized capitalization stocks. The following information is intended to help you better understand some of the risks of investing in the Fund. The impact of the following risks on the Fund may vary depending on the Fund’s investments. The greater the Fund’s investment in a particular security, the greater the Fund’s exposure to the risks associated with that security. Before investing in the Fund, you should consider carefully the risks that you assume when investing in the Fund.

Index Tracking Risk. Tracking error refers to the risk that Janus Capital may not be able to cause the Fund’s performance to match or correlate to that of the Underlying Index, either on a daily or aggregate basis. There are a number of factors that may contribute to the Fund’s tracking error, such as Fund expenses, imperfect correlation between the Fund’s investments and those of the Underlying Index, rounding of share prices, the timing or magnitude of changes to the composition of the Underlying Index, regulatory policies, and a high portfolio turnover rate. The Fund incurs operating expenses not applicable to the Underlying Index and incurs costs associated with buying and selling securities, especially when rebalancing the Fund’s securities holdings to reflect changes in the composition of the Underlying Index. In addition, mathematical compounding may prevent the Fund from correlating with the monthly, quarterly, annual, or other period performance of the Underlying Index. Tracking error may cause the Fund’s performance to be less than expected.

Passive Investment Risk. The Fund is not actively managed. Therefore, unless a specific security is removed from the Underlying Index, or the selling of shares of that security is otherwise required upon a rebalancing of the Underlying Index pursuant to the Underlying Index methodology, the Fund generally would not sell a security because the security’s issuer was in financial trouble. If a specific security is removed from the Underlying Index, the Fund may be forced to sell such security at an inopportune time or for a price other than the security’s current market value. An investment in the Fund involves risks similar to those of investing in equity securities traded on an exchange, such as market fluctuations caused by such factors as economic and political developments, changes in interest rates and perceived trends in security prices. It is anticipated that the value of Fund shares will decline, more or less, in correspondence with any decline in value of the Underlying Index. The Underlying Index may not contain the appropriate mix of securities for any particular point in the business cycle of the overall economy, particular economic sectors, or narrow industries within which the commercial activities of the companies

7 ï Janus Detroit Street Trust

composing the portfolio securities holdings of the Fund are conducted, and the timing of movements from one type of security to another in seeking to replicate the Underlying Index could have a negative effect on the Fund. Unlike with an actively managed fund, the Janus Capital does not use techniques or defensive strategies designed to lessen the effects of market volatility or to reduce the impact of periods of market decline. This means that, based on market and economic conditions, the Fund’s performance could be lower than other types of mutual funds that may actively shift their portfolio assets to take advantage of market opportunities or to lessen the impact of a market decline.

Fluctuation of NAV. The NAV of the Fund shares will generally fluctuate with changes in the market value of the Fund’s securities holdings. The market prices of shares will generally fluctuate in accordance with changes in the Fund’s NAV and supply and demand of shares on the NASDAQ. It cannot be predicted whether Fund shares will trade below, at or above their NAV. Price differences may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for shares will be closely related to, but not identical to, the same forces influencing the prices of the securities of the Underlying Index trading individually or in the aggregate at any point in time. The market prices of Fund shares may deviate significantly from the NAV of the shares during periods of market volatility. While the creation/redemption feature is designed to make it likely that Fund shares normally will trade close to the Fund’s NAV, disruptions to creations and redemptions may result in trading prices that differ significantly from the Fund’s NAV. An absence of trading in shares of the Fund, or a high volume of trading in the Fund, may result in trading prices that differ significantly from the Fund’s NAV. If an investor purchases Fund shares at a time when the market price is at a premium to the NAV of the shares or sells at a time when the market price is at a discount to the NAV of the shares, then the investor may sustain losses.

Costs of Buying or Selling Shares. Investors buying or selling Fund shares in the secondary market will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of shares. In addition, secondary market investors will also incur the cost of the difference between the price that an investor is willing to pay for shares (the “bid” price) and the price at which an investor is willing to sell shares (the “ask” price). This difference in bid and ask prices is often referred to as the “spread” or “bid/ask spread.” The bid/ask spread varies over time for shares based on trading volume and market liquidity, and is generally lower if the Fund’s shares have more trading volume and market liquidity and higher if the Fund’s shares have little trading volume and market liquidity. Further, increased market volatility may cause increased bid/ask spreads. Due to the costs of buying or selling shares, including bid/ask spreads, frequent trading of shares may significantly reduce investment results and an investment in shares may not be advisable for investors who anticipate regularly making small investments.

Trading Issues Risk. Trading in shares on the NASDAQ may be halted due to market conditions or for reasons that, in the view of the NASDAQ, make trading in shares inadvisable. In addition, trading in shares on the NASDAQ is subject to trading halts caused by extraordinary market volatility pursuant to the NASDAQ “circuit breaker” rules. There can be no assurance that the requirements of the NASDAQ necessary to maintain the listing of the Fund will continue to be met or will remain unchanged. While the creation/redemption feature is designed to make it likely that shares will trade close to the Fund’s NAV, disruptions to creations and redemptions may result in trading prices that differ significantly from the Fund’s NAV. If an investor purchases shares at a time when the market price is at a premium to the NAV of the shares or sells at a time when the market price is at a discount to the NAV of the shares, then the investor may sustain losses.

Real Estate Securities Risk. Although not considered a principal risk, the Fund’s performance may be affected by the risks associated with investments in real estate-related companies. The value of real estate-related companies’ securities is sensitive to changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements, supply and demand, and the management skill and creditworthiness of the company. Investments in REITs involve the same risks as other real estate investments. In addition, a REIT could fail to qualify for tax-free pass-through of its income under the Internal Revenue Code or fail to maintain its exemption from registration under the Investment Company Act of 1940, as amended, which could produce adverse economic consequences for the REIT and its investors, including the Fund.

These risks are described further in the Statement of Additional Information.

INFORMATION REGARDING THE UNDERLYING INDEX

The Underlying Index is composed of common stocks that are selected by the Index Provider from a universe of 2,000 small-sized capitalization stocks. The Underlying Index is designed to select small-sized capitalization stocks which are poised for “smart growth” by evaluating each company’s performance in three critical areas: growth, profitability, and capital efficiency.

8 ï Janus Detroit Street Trust

The Index Provider scores such stocks based on fundamental measures of their growth, profitability, and capital efficiency, and selects the top 10% of such eligible stocks scoring the highest using a proprietary quantitative methodology. To arrive at the top 10%, for each security in the stated universe, the quantitative methodology assigns a score in each of 10 different factors, relative to other eligible securities. The fundamental factors include measures that Janus Capital believes are tied to a stock’s outperformance relative to other small cap stocks, and indicate a company’s performance with respect to growth (such as the revenue growth rate over 2- 5- and 8- year periods), profitability (such as margin expansion, profit margin and earnings per share over time) and capital efficiency (such as returns on invested capital). An eligible security is given a decile score and may also receive additional points for exceeding an established threshold. Each stock in the eligible universe will receive a point total equal to the decile rank of the stock for a given factor. For example, if a stock is in the top decile for a given factor, it will receive 10 points for that factor. If the stock is in the lowest decile, it will receive 1 point. For each factor, a threshold is established, and to the extent a stock’s score within a factor meets or exceeds the threshold, it will receive additional points. A high threshold means that exceeding that threshold is relatively difficult for a stock to achieve, and as a result will receive more bonus points than if the threshold were lower. For detailed information on how stocks are scored, see the Janus Small Cap Growth Alpha Index Methodology document, available at the Index Provider’s website.

The scores for each factor are then added together, with equal weighting, to arrive at an overall score. These stocks are then weighted within the Underlying Index according to their market capitalization. Finally, the stocks are sector-weighted to reflect the sector allocation weight of Janus Venture Fund, based on its most recent publicly available holdings. A stock may not represent more than 3% of the Underlying Index. The Underlying Index seeks risk adjusted outperformance relative to a market capitalization weighted universe of small-sized capitalization growth stocks. Market capitalizations within the Underlying Index will vary, but as of January 29, 2016, they ranged from approximately $53 million to $5.4 billion. The Underlying Index is rebalanced on a quarterly basis based the methodology described above.

The Underlying Index is compiled and administered by Janus Index Services, an affiliate of the Fund and Janus Capital.

9 ï Janus Detroit Street Trust

Management of the Fund

INVESTMENT ADVISER

Janus Capital Management LLC, 151 Detroit Street, Denver, Colorado 80206-4805, is the investment adviser to the Fund. Janus Capital is responsible for the day-to-day management of the Fund’s investment portfolio and furnishes continuous advice and recommendations concerning the Fund’s investments. Janus Capital also provides certain administration and other services and is responsible for other business affairs of the Fund.

Janus Capital (together with its predecessors) has served as investment adviser to Janus mutual funds since 1970 and currently serves as investment adviser to all of the Janus funds, acts as subadviser for a number of private-label mutual funds, and provides separate account advisory services for institutional accounts and other unregistered products.

Janus Capital has received an exemptive order from the Securities and Exchange Commission that permits Janus Capital, subject to the approval of the Trustees, to appoint or replace certain subadvisers to manage all or a portion of the Fund’s assets and enter into, amend, or terminate a subadvisory agreement with certain subadvisers without obtaining shareholder approval (a “manager-of-managers structure”). The manager-of-managers structure applies to subadvisers that are not affiliated with the Trust or Janus Capital (“non-affiliated subadvisers”), as well as any subadviser that is an indirect or direct “wholly-owned subsidiary” (as such term is defined by the 1940 Act) of Janus Capital or of another company that, indirectly or directly, wholly owns Janus Capital (collectively, “wholly-owned subadvisers”).

Pursuant to the order, Janus Capital, with the approval of the Trustees, has the discretion to terminate any subadviser and allocate and reallocate the Fund’s assets among Janus Capital and any other non-affiliated subadvisers or wholly-owned subadvisers (including terminating a non-affiliated subadviser and replacing it with a wholly-owned subadviser). Janus Capital, subject to oversight and supervision by the Trustees, has responsibility to oversee any subadviser to the Fund and to recommend for approval by the Trustees, the hiring, termination, and replacement of subadvisers for the Fund. The order also permits the Fund to disclose subadvisers’ fees only in the aggregate in the SAI. In the event that Janus Capital hires a new subadviser pursuant to the manager-of-managers structure, the Fund would provide shareholders with information about the new subadviser and subadvisory agreement within 90 days.

The Trustees and the initial shareholder of the Fund have approved the use of a manager-of-managers structure for the Fund.

MANAGEMENT EXPENSES

Under its unitary fee structure, the Fund pays Janus Capital a “Management Fee” in return for providing certain investment advisory, supervisory, and administrative services to the Fund, including the costs of transfer agency, custody, fund administration, legal, audit, and other services. Janus Capital’s fee structure is designed to pay substantially all of the Fund’s expenses. However, the Fund bears 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 distribution fees (if any), brokerage expenses or commissions, interest, dividends, taxes, litigation expenses, acquired fund fees and expenses (if any), and extraordinary expenses.

The Fund’s Management Fee is calculated daily and paid monthly. The Fund’s advisory agreement details the Management Fee and other expenses that the Fund must pay.

The following table reflects the Fund’s contractual Management Fee rate (expressed as an annual rate). The rate shown is a fixed rate based on the Fund’s average daily net assets.

A discussion regarding the basis for the Trustees’ approval of the Fund’s investment advisory agreement will be included in the Fund’s annual report (for the period ending October 31) or semiannual report (for the period ending April 30) to shareholders, following such approval. You can request the Fund’s annual or semiannual reports (as they become available), free of charge, by contacting your broker-dealer, plan sponsor, or financial intermediary, or by contacting a Janus representative at 1-877-335-2687. The reports are also available, free of charge, at janus.com/etfs.

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INVESTMENT PERSONNEL

Janus Small Cap Growth Alpha ETF

Co-Portfolio Managers Benjamin Wang and Scott M. Weiner jointly share responsibility for the day-to-day management of the Fund, with no limitation on the authority of one co-portfolio manager in relation to the other.

Benjamin Wang, CFA, is Co-Portfolio Manager of the Fund, which he has co-managed since February 2016. He is also Portfolio Manager of other Janus accounts. Mr. Wang joined Janus Capital in November 2014 following Janus Capital’s acquisition of VelocityShares, LLC. Prior to joining Janus Capital, Mr. Wang was Vice President at VelocityShares, LLC from 2012 to 2014, and an execution trader at Goldman Sachs Asset Management from 2007 to 2012. He holds a Bachelor of Science degree and a Master of Engineering in Computer Science from the Massachusetts Institute of Technology, and a Master of Science degree in Financial Engineering from Columbia University. Mr. Wang holds the Chartered Financial Analyst designation.

Scott M. Weiner, DPhil, is Co-Portfolio Manager of the Fund, which he has co-managed since February 2016. He is also Portfolio Manager of other Janus accounts. Mr. Weiner joined Janus Capital in November 2014 following Janus Capital’s acquisition of VelocityShares, LLC. Prior to joining Janus Capital, Mr. Weiner was Managing Director at VelocityShares, LLC from 2011 to 2014, and Managing Director and U.S. Head of Equity Derivatives and Quantitative Strategy at Deutsche Bank from 2005 to 2010. He holds a Finance degree from the Wharton School of the University of Pennsylvania, a Master’s degree in Economics from the University of Oxford, and also received his Doctorate in Economics from the University of Oxford.

Information about the portfolio managers’ compensation structure and other accounts managed is included in the SAI.

Conflicts of Interest

Janus Capital manages many funds and numerous other accounts, which may include separate accounts and other pooled investment vehicles, such as hedge funds. Side-by-side management of multiple accounts, including the management of a cash collateral pool for securities lending and investing the Janus funds’ cash, may give rise to conflicts of interest among those accounts, and may create potential risks, such as the risk that investment activity in one account may adversely affect another account. For example, short sale activity in an account could adversely affect the market value of long positions in one or more other accounts (and vice versa). Side-by-side management may raise additional potential conflicts of interest relating to the allocation of investment opportunities and the aggregation and allocation of trades. A further discussion of potential conflicts of interest and a discussion of certain procedures intended to mitigate such potential conflicts are contained in the Fund’s SAI.

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Other information

DISTRIBUTION OF THE FUND

Creation Units for the Fund are distributed by ALPS Distributors, Inc. (the “Distributor”), which is a member of the Financial Industry Regulatory Authority, Inc. (“FINRA”). To obtain information about FINRA member firms and their associated persons, you may contact FINRA at www.finra.org, or 1-800-289-9999.

INDEX PROVIDER

Janus Index & Calculation Services LLC (“Janus Index Services”) is the Index Provider for the Underlying Index. Janus Capital has entered into a license agreement with Janus Index Services to use the Underlying Index. Janus Index Services is affiliated with the Fund and Janus Capital. This affiliation may create potential conflicts for Janus Index Services as it may have an interest in the performance of the Fund, which could motivate it to alter the Underlying Index methodology for the Underlying Index. Janus Index Services has adopted procedures that it believes are reasonably designed to mitigate these and other potential conflicts.

Disclaimers

Janus Index Services is the licensor of certain trademarks, service marks, and trade names.

Neither Janus Index Services nor any of its affiliates make any representation or warranty, express or implied, to the owners of the Fund or any member of the public regarding the advisability of investing in securities generally or in the Fund particularly or the ability of the Underlying Index to track general market performance. The Underlying Index is determined, composed, and calculated by Janus Index Services without regard to Janus Capital or the Fund. Janus Index Services has no obligation to take the needs of Janus Capital or the owners of the Fund into consideration in determining, composing, or calculating the Underlying Index. Janus Index Services is not responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Fund to be issued or in the determination or calculation of the equation by which the Fund is to be converted into cash.

ALTHOUGH JANUS INDEX SERVICES SHALL OBTAIN INFORMATION FOR INCLUSION IN OR FOR USE IN THE CALCULATION OF THE UNDERLYING INDEX FROM SOURCES WHICH IT CONSIDERS RELIABLE, IT DOES NOT GUARANTEE THE QUALITY, ACCURACY AND/OR THE COMPLETENESS OF THE UNDERLYING INDEX OR ANY DATA INCLUDED THEREIN AND SHALL HAVE NO LIABILITY FOR ERRORS OR OMISSIONS OF ANY KIND RELATED TO THE UNDERLYING INDEX OR DATA. JANUS INDEX SERVICES MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY JANUS CAPITAL, OWNERS OF THE FUND, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE UNDERLYING INDEX OR ANY DATA INCLUDED THEREIN IN CONNECTION WITH THE RIGHTS LICENSED TO JANUS CAPITAL FOR ANY OTHER USE. JANUS INDEX SERVICES MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE UNDERLYING INDEX OR ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL IT HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

Janus Capital does not guarantee the accuracy and/or the completeness of the Underlying Index or any data included therein, and Janus Capital shall have no liability for any errors, omissions or interruptions therein. Janus Capital makes no warranty, express or implied, as to results to be obtained by the Fund, owners of the shares of the Fund or any other person or entity from the use of the Underlying Index or any data included therein. Janus Capital makes no express or implied warranties, and expressly disclaims all warranties of merchantability or fitness for a particular purpose or use with respect to the Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall Janus Capital have any liability for any special, punitive, direct, indirect or consequential damages (including lost profits) arising out of matters relating to the use of the Underlying Index even if notified of the possibility of such damages.

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Dividends, distributions, and taxes

DISTRIBUTIONS

To avoid taxation of the Fund, the Internal Revenue Code requires the Fund to distribute all or substantially all of its net investment income and any net capital gains realized on its investments at least annually.

Distribution Schedule

Income dividends, if any, are distributed to shareholders quarterly. Net capital gains are distributed at least annually. Dividends may be declared and paid more frequently to improve Underlying Index tracking or to comply with the distribution requirements of the Internal Revenue Code. The date you receive your distribution may vary depending on how your intermediary processes trades. Dividend payments are made through Depository Trust Company (“DTC”) participants and indirect participants to beneficial owners then of record with proceeds received from the Fund. Please consult your intermediary for details.

How Distributions Affect the Fund’s NAV

Distributions, other than daily income dividends, are paid to shareholders as of the record date of a distribution of the Fund, regardless of how long the shares have been held. Undistributed income and net capital gains are included in the Fund’s daily net asset value (“NAV”). The Fund’s NAV drops by the amount of the distribution, net of any subsequent market fluctuations. For example, assume that on December 31, the Fund declared a dividend in the amount of $0.25 per share. If the Fund’s NAV was $10.00 on December 30, the Fund’s NAV on December 31 would be $9.75, barring market fluctuations. You should be aware that distributions from a taxable fund do not increase the value of your investment and may create income tax obligations.

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.

TAXES

As with any investment, you should consider the tax consequences of investing in the Fund. The following is a general discussion of certain federal income tax consequences of investing in the Fund. The discussion does not apply to qualified tax-deferred accounts or other non-taxable entities, nor is it a complete analysis of the federal income tax implications of investing in the Fund. You should consult your tax adviser regarding the effect that an investment in the Fund may have on your particular tax situation, including the federal, state, local, and foreign tax consequences of your investment.

Taxes on Distributions

Distributions by the Fund are subject to federal income tax, regardless of whether the distribution is made in cash or reinvested in additional shares of the Fund. Distributions from net investment income (which includes dividends, interest, and realized net short-term capital gains), other than qualified dividend income, are taxable to shareholders as ordinary income. Distributions of qualified dividend income are taxed to individuals and other noncorporate shareholders at long-term capital gain rates, provided certain holding period and other requirements are satisfied. Distributions of net capital gain (i.e., the excess of net long-term capital gain over net short-term capital loss) are taxable as long-term capital gain, regardless of how long a shareholder has held Fund shares. Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to an additional 3.8% Medicare contribution tax on net investment income. Net investment income includes dividends paid by the Fund and capital gains from any sale or exchange of Fund shares. The Fund’s net investment income and capital gains are distributed to (and may be taxable to) those persons who are shareholders of the Fund at the record date of such payments. Although the Fund’s total net income and net realized gain are the results of its operations, the per share amount distributed or taxable to shareholders is affected by the number of Fund shares outstanding at the record date. Distributions declared to shareholders of record in October, November, or December and paid on or before January 31 of the succeeding year will be treated for federal income tax purposes as if received by shareholders on December 31 of the year in which the distribution was declared. Generally, account tax information will be made available to shareholders on or before February 15 of each year. Information regarding distributions may also be reported to the Internal Revenue Service.

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Taxes on Sales

Any time you sell the shares of the Fund in a taxable account, it is considered a taxable event. Depending on the purchase price and the sale price, you may have a gain or loss on the transaction. The gain or loss will generally be treated as a long-term capital gain or loss if you held your shares for more than one year and if not held for such period, as a short-term capital gain or loss. Any tax liabilities generated by your transactions are your responsibility.

The Fund may be required to withhold U.S. federal income tax on all distributions payable to shareholders who fail to provide their correct taxpayer identification number, fail to make certain required certifications, or who have been notified by the Internal Revenue Service that they are subject to backup withholding. The current backup withholding rate is applied.

For shares purchased on or after January 1, 2012 and sold thereafter from a taxable account, your intermediary will report cost basis information to you and to the IRS. Your intermediary will permit shareholders to elect their preferred cost basis method. In the absence of an election, your cost basis method will be your intermediary’s default method, which is often the average cost method. Please consult your tax adviser to determine the appropriate cost basis method for your particular tax situation and to learn more about how the cost basis reporting laws apply to you and your investments.

Taxation of the Fund

Dividends, interest, and some capital gains received by the Fund on foreign securities may be subject to foreign tax withholding or other foreign taxes.

Certain fund transactions may involve short sales, futures, options, swap agreements, hedged investments, and other similar transactions, and may be subject to special provisions of the Internal Revenue Code that, among other things, can potentially affect the character, amount, and timing of distributions to shareholders, and utilization of capital loss carryforwards. The Fund will monitor its transactions and may make certain tax elections and use certain investment strategies where applicable in order to mitigate the effect of these tax provisions, if possible.

The Fund does not expect to pay any federal income or excise taxes because it intends to meet certain requirements of the Internal Revenue Code, including the distribution each year of substantially all its net investment income and net capital gains. It is important for the Fund to meet these requirements so that any earnings on your investment will not be subject to federal income taxes twice. If the Fund invests in a partnership, however, it may be subject to state tax liabilities.

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Shareholder’s guide

The Fund issues or redeems its shares at NAV per share only in Creation Units. Shares of the Fund are listed for trading on a national securities exchange and trade on the secondary market during the trading day. Shares can be bought and sold throughout the trading day like shares of other publicly traded companies. There is no minimum investment. When buying or selling Fund shares through a broker, you will incur customary brokerage commissions and charges, and you may pay some or all of the spread between the bid and offered price in the secondary market on each purchase and sale transaction. Fund shares are traded on the NASDAQ under the trading symbol JSML. Share prices are reported in dollars and cents per share.

Authorized Participants may acquire Fund shares directly from the Fund, and Authorized Purchasers may tender their Fund shares for redemption directly to the Fund, at NAV per share, only in Creation Units and in accordance with the procedures described in the SAI.

PRICING OF FUND SHARES

The per share NAV of the Fund is computed by dividing the total value of the Fund’s portfolio, less any liabilities, by the total number of outstanding shares of the Fund. The Fund’s NAV is calculated as of the close of the regular trading session of the New York Stock Exchange (“NYSE”) (normally 4:00 p.m. New York time) each day that the NYSE is open (“Business Day”). However, the NAV may still be calculated if trading on the NYSE is restricted, provided there is sufficient pricing information available for the Fund to value its securities, or as permitted by the Securities and Exchange Commission (“SEC”). Foreign securities held by the Fund may be traded on days and at times when the NYSE is closed and the NAV is therefore not calculated. Accordingly, the value of the Fund’s holdings may change on days that are not Business Days in the United States and on which you will not be able to purchase or sell the Fund’s shares.

Securities held by the Fund are valued in accordance with policies and procedures established by and under the supervision of the Trustees. To the extent available, equity securities are generally valued on the basis of market quotations. Most fixed-income securities are typically valued using an evaluated bid price supplied by an approved pricing service that is intended to reflect market value. The evaluated bid price is an evaluation that may consider factors such as security prices, yields, maturities, and ratings. Certain short-term instruments maturing within 60 days or less may be valued at amortized cost, which approximates market value. If a market quotation or evaluated price for a security is not readily available or is deemed unreliable, or if an event that is expected to affect the value of the security occurs after the close of the principal exchange or market on which the security is traded, and before the close of the NYSE, a fair value of the security will be determined in good faith under the policies and procedures. Such events include, but are not limited to: (i) a significant event that may affect the securities of a single issuer, such as a merger, bankruptcy, or significant issuer-specific development; (ii) an event that may affect an entire market, such as a natural disaster or significant governmental action; (iii) a non-significant event such as a market closing early or not opening, or a security trading halt; and (iv) pricing of a non-valued security and a restricted or non-public security. This type of fair value pricing may be more commonly used with foreign equity securities, but it may also be used with, among other things, thinly-traded domestic securities or fixed-income securities. Special valuation considerations may apply with respect to “odd-lot” fixed-income transactions which, due to their small size, may receive evaluated prices by pricing services which reflect a large block trade and not what actually could be obtained for the odd-lot position. For valuation purposes, quotations of foreign portfolio securities, other assets and liabilities, and forward contracts stated in foreign currency are generally translated into U.S. dollar equivalents at the prevailing market rates. The Fund uses systematic fair valuation models provided by independent pricing services to value foreign equity securities in order to adjust for stale pricing, which may occur between the close of certain foreign exchanges and the close of the NYSE.

The value of the securities of mutual funds held by the Fund, if any, will be calculated using the NAV of such mutual funds, and the prospectuses for such mutual funds explain the circumstances under which they use fair value pricing and the effects of using fair value pricing.

All purchases, sales, or other account activity must be processed through your financial intermediary or plan sponsor.

DISTRIBUTION AND SERVICING FEES

Distribution and Shareholder Servicing Plan

The Trust has adopted a Distribution and Servicing Plan for shares of the Fund pursuant to Rule 12b-1 under the 1940 Act (the “Plan”). The Plan permits compensation in connection with the distribution and marketing of Fund shares and/or the provision of certain shareholder services. The Plan permits the Fund to pay the Distributor or its designee, a fee for the sale

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and distribution and/or shareholder servicing of the shares at an annual rate of up to 0.25% of average daily net assets of the shares of the Fund. However, the Trustees have determined not to authorize payment of a 12b-1 Plan fee at this time.

Under the terms of the Plan, the Trust is authorized to make payments to the Distributor or its designee for remittance to retirement plan service providers, broker-dealers, bank trust departments, financial advisors, and other financial intermediaries, as compensation for distribution and/or shareholder services performed by such entities for their customers who are investors in the Fund.

The 12b-1 fee may only be imposed or increased when the Trustees determine 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 Plan fee may cost an investor more than other types of sales charges.

PAYMENTS TO FINANCIAL INTERMEDIARIES BY JANUS CAPITAL OR ITS AFFILIATES

From their own assets, Janus Capital or its affiliates may pay selected brokerage firms or other financial intermediaries for making the Funds available to their clients or otherwise distributing, promoting or marketing the Funds. Janus Capital or its affiliates may also make payments to intermediaries for information about transactions and holdings in the Funds, such as the amount of Fund shares purchased, sold or held through the intermediary and or its salespersons, the intermediary platform(s) on which shares are transacted and other information related to the Funds. Janus Capital or its affiliates may also make payments to intermediaries to eliminate or reduce trading commissions that the intermediary would otherwise charge its customers or its salespersons in connection with the purchase or sale of certain Funds. Payment by Janus Capital or its affiliates to eliminate or reduce a trading commission creates an incentive for salespersons of the intermediary to sell the Janus funds over other funds for which a commission would be charged. The amount of these payments is determined from time to time by Janus Capital, may be substantial, and may differ for different intermediaries. More information regarding these payments is contained in the Statement of Additional Information.

With respect to non-exchange-traded Janus funds not offered in this Prospectus, Janus Capital or its affiliates may pay fees, from their own assets, to selected brokerage firms, banks, financial advisors, retirement plan service providers, and other financial intermediaries that sell the Janus funds for distribution, marketing, promotional, or related services, and/or for providing recordkeeping, subaccounting, transaction processing, and other shareholder or administrative services (including payments for processing transactions via National Securities Clearing Corporation (“NSCC”) or other means) in connection with investments in the Janus funds. These fees are in addition to any fees that may be paid by the Janus funds for these types of services or other services. Shareholders investing through an intermediary should consider whether such arrangements exist when evaluating any recommendations from an intermediary.

In addition, Janus Capital or its affiliates may also share certain marketing expenses with intermediaries, or pay for or sponsor informational meetings, seminars, client awareness events, support for marketing materials, sales reporting, or business building programs for such intermediaries to raise awareness of the Janus funds. Janus Capital or its affiliates may make payments to participate in intermediary marketing support programs which may provide Janus Capital or its affiliates with one or more of the following benefits: attendance at sales conferences, participation in meetings or training sessions, access to or information about intermediary personnel, use of an intermediary’s marketing and communication infrastructure, fund analysis tools, business planning and strategy sessions with intermediary personnel, information on industry- or platform-specific developments, trends and service providers, and other marketing-related services. Such payments may be in addition to, or in lieu of, the payments described above. These payments are intended to promote the sales of Janus funds and to reimburse financial intermediaries, directly or indirectly, for the costs that they or their salespersons incur in connection with educational seminars, meetings, and training efforts about the Janus funds to enable the intermediaries and their salespersons to make suitable recommendations, provide useful services, and maintain the necessary infrastructure to make the Janus funds available to their customers.

The receipt of (or prospect of receiving) payments, reimbursements and other forms of compensation described above may provide a financial intermediary and its salespersons with an incentive to favor sales of Janus funds’ shares over sales of other funds (or non-mutual fund investments), with respect to which the financial intermediary does not receive such payments or receives them in a lower amount. The receipt of these payments may cause certain financial intermediaries to elevate the prominence of the Janus funds within such financial intermediary’s organization by, for example, placement on a list of

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preferred or recommended funds and/or the provision of preferential or enhanced opportunities to promote the Janus funds in various ways within such financial intermediary’s organization.

From time to time, certain financial intermediaries approach Janus Capital to request that Janus Capital make contributions to certain charitable organizations. In these cases, Janus Capital’s contribution may result in the financial intermediary, or its salespersons, recommending Janus funds over other funds (or non-mutual fund investments).

The payment arrangements described above will not change the price an investor pays for shares nor the amount that a Janus fund receives to invest on behalf of the investor. You should consider whether such arrangements exist when evaluating any recommendations from an intermediary to purchase or sell shares of the Funds. Please contact your financial intermediary or plan sponsor for details on such arrangements.

PURCHASING AND SELLING SHARES

Shares of the Fund 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 Fund does not impose any minimum investment for shares of the Fund purchased on an exchange. Buying or selling the Fund’s shares involves certain costs that apply to all securities transactions. When buying or selling shares of the 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 the 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 the Fund may be acquired through the Distributor or redeemed directly with the Fund only in Creation Units or multiples thereof, as discussed in the “Creation and Redemption of Creation Units” section of the Statement of Additional Information. Once created, shares of the Fund generally trade in the secondary market in amounts less than a Creation Unit.

The Fund’s primary listing exchange is the NASDAQ. The NASDAQ 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 Fund is each day the NASDAQ is open. Orders from Authorized Participants to create or redeem Creation Units will only be accepted on a Business Day. On days when the NASDAQ closes earlier than normal, the Fund may require orders to create or redeem Creation Units to be placed earlier in the day. See the Statement of Additional Information for more information.

In compliance with the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 (“USA PATRIOT Act”), your financial intermediary is required to verify certain information on your account application as part of its Anti-Money Laundering Program. You will be required to provide your full name, date of birth, social security number, and permanent street address to assist in verifying your identity. You may also be asked to provide documents that may help to establish your identity. Until verification of your identity is made, your financial intermediary may temporarily limit additional share purchases. In addition, your financial intermediary may close an account if it is unable to verify a shareholder’s identity. Please contact your financial intermediary if you need additional assistance when completing your application or additional information about the intermediary’s Anti-Money Laundering Program.

In an effort to ensure compliance with this law, Janus’ Anti-Money Laundering Program (the “Program”) provides for the development of internal practices, procedures and controls, designation of anti-money laundering compliance officers, an ongoing training program, and an independent audit function to determine the effectiveness of the Program.

Continuous Offering

The method by which Creation Units of shares are created and traded may raise certain issues under applicable securities laws. Because new Creation Units of shares are issued and sold by the Fund on an ongoing basis, a “distribution,” as such term is used in the Securities Act of 1933, as amended (the “Securities Act”), may occur at any point. Broker-dealers and other persons are cautioned that some activities on their part may, depending on the circumstances, result in their being

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deemed participants in a distribution in a manner which could render them statutory underwriters and subject them to the prospectus delivery requirements and liability provisions of the Securities Act. For example, a broker-dealer firm or its client may be deemed a statutory underwriter if it takes Creation Units after placing an order with the Distributor, breaks them down into constituent shares and sells the shares directly to customers or if it chooses to couple the creation of a supply of new shares with an active selling effort involving solicitation of secondary market demand for shares. A determination of whether one is an underwriter for purposes of the Securities Act must take into account all the facts and circumstances pertaining to the activities of the broker-dealer or its client in the particular case, and the examples mentioned above should not be considered a complete description of all the activities that could lead to a characterization as an underwriter.

Broker-dealer firms should also note that dealers who are not “underwriters” but are effecting transactions in shares, whether or not participating in the distribution of shares, are generally required to deliver a prospectus. This is because the prospectus delivery exemption in Section 4(a)(3)(C) of the Securities Act is not available in respect of such transactions as a result of Section 24(d) of the 1940 Act. As a result, broker-dealer firms should note that dealers who are not “underwriters” but are participating in a distribution (as contrasted with engaging in ordinary secondary market transactions) and thus dealing with the shares that are part of an overallotment within the meaning of Section 4(a)(3)(C) of the Securities Act, will be unable to take advantage of the prospectus delivery exemption provided by Section 4(a)(3) of the Securities Act. For delivery of prospectuses to exchange members, the prospectus delivery mechanism of Rule 153 under the Securities Act is only available with respect to transactions on a national exchange.

Book Entry

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

Investors owning shares of the Fund are beneficial owners as shown on the records of DTC or its participants. DTC serves as the securities depository for shares of the Fund. 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.

Share Prices

The trading prices of the 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 intra-day net asset value of the 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 intra-day net asset value is based on the current market value of the securities and/or cash included in the Fund’s intra-day net asset value basket. The intra-day net asset value does not necessarily reflect the precise composition of the current portfolio of securities and instruments held by the Fund at a particular point in time or the best possible valuation of the current portfolio. Therefore, the intra-day net asset value should not be viewed as a “real-time” update of the NAV, which is computed only once a day. The intra-day net asset value 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 the Fund’s intra-day net asset value basket. The Fund is not involved in, or responsible for, the calculation or dissemination of the intra-day net asset value and makes no representation or warranty as to its accuracy. An inaccuracy in the intra-day net asset value could result from various factors, including the difficulty of pricing portfolio instruments on an intra-day basis.

Premiums and Discounts

There may be differences between the daily market prices on secondary markets for shares of the Fund and the Fund’s NAV. NAV is the price per share at which the Fund issues and redeems shares. See “Pricing of Fund Shares” above. The price used to calculate market returns (“Market Price”) of the 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. The Fund’s Market Price may be at, above, or below its NAV. The NAV of the Fund will fluctuate with changes in the market value of its portfolio holdings. The Market Price of the Fund will fluctuate in accordance with changes in its NAV, as well as market supply and demand.

18 ï Janus Detroit Street Trust

Premiums or discounts are the differences (expressed as a percentage) between the NAV and the Market Price of the Fund on a given day, generally at the time the NAV is calculated. A premium is the amount that the Fund is trading above the reported NAV, expressed as a percentage of the NAV. A discount is the amount that the 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 the Fund’s four previous calendar quarters (or for the life of the Fund, if shorter) will be available at janus.com/etfs.

Investments by Other Investment Companies

The Trust and the Fund are part of the Janus family of funds and are related for purposes of investor and investment services, as defined in Section 12(d)(1)(G) of the 1940 Act.

For purposes of the 1940 Act, Fund shares are issued by a registered investment company and purchases of Fund shares by registered investment companies and companies relying on Section 3(c)(1) or 3(c)(7) of the Act are subject to the restrictions set forth in Section 12(d)(1) of the Act, except as permitted by an exemptive order of the SEC. The SEC has granted the Trust such an order to permit registered investment companies to invest in Fund shares beyond the limits in Section 12(d)(1)(A), subject to certain terms and conditions, including that the registered investment company first enter into a written agreement with the Trust regarding the terms of the investment.

EXCESSIVE TRADING

Frequent trading of Fund shares does not disrupt portfolio management, increase the Fund’s trading costs, lead to realization of capital gains by the Fund, or otherwise harm Fund shareholders. The vast majority of trading in Fund shares occurs on the secondary market. Because these trades do not involve the Fund, they do not harm the Fund or its shareholders. A few institutional investors are authorized to purchase and redeem Fund shares directly with the Fund. Because these trades typically are effected in kind (i.e., for securities and not for cash), they do not cause any of the harmful effects to the issuing fund (as previously noted) that may result from frequent cash trades. For these reasons, the Trustees of the Fund have determined that it is not necessary to adopt policies and procedures to detect and deter frequent trading and market timing of Fund shares. However, the Fund’s policies and procedures regarding frequent purchases and redemptions may be modified by the Trustees at any time.

AVAILABILITY OF PORTFOLIO HOLDINGS INFORMATION

Each business day, the Fund’s portfolio holdings information is provided to the Distributor or other agent for dissemination through the facilities of the NSCC and/or other fee-based subscription services to NSCC members and/or subscribers to entities that publish and/or analyze such information in connection with the process of purchasing or redeeming Creation Units or trading shares of the Fund in the secondary market. In addition, on each business day before commencement of trading in shares on the NASDAQ, the Fund will disclose on janus.com/etfs the identities and quantities of each portfolio position held by the Fund that will form the basis for the Fund’s calculation of the NAV per share at the end of the business day. The Fund is also required to disclose its complete holdings in the quarterly holdings report on Form N-Q within 60 days of the end of the first and third fiscal quarters, and in the annual report and semiannual report to Fund shareholders.

For additional information on these disclosures and the availability of portfolio holdings information, please refer to the Fund’s SAI.

SHAREHOLDER COMMUNICATIONS

Statements and Reports

Your financial intermediary or plan sponsor is responsible for sending you periodic statements of all transactions, along with trade confirmations and tax reporting, as required by applicable law.

Your financial intermediary or plan sponsor is responsible for providing annual and semiannual reports, including the financial statements of the Fund. These reports show the Fund’s investments and the market value of such investments, as well as other information about the Fund and its operations. Please contact your financial intermediary or plan sponsor to obtain these reports. The Fund’s fiscal year ends October 31.

19 ï Janus Detroit Street Trust

Lost (Unclaimed/Abandoned) Accounts

It is important to maintain a correct address for each shareholder. An incorrect address may cause a shareholder’s account statements and other mailings to be returned as undeliverable. Based upon statutory requirements for returned mail, your financial intermediary or plan sponsor is required to attempt to locate the shareholder or rightful owner of the account. If the financial intermediary or plan sponsor is unable to locate the shareholder, then the financial intermediary or plan sponsor is legally obligated to deem the property “unclaimed” or “abandoned,” and subsequently escheat (or transfer) unclaimed property (including shares of a fund) to the appropriate state’s unclaimed property administrator in accordance with statutory requirements. Further, your account may be deemed “unclaimed” or “abandoned,” and subsequently transferred to your state of residence if no activity (as defined by that state) occurs within your account during the time frame specified in your state’s unclaimed property laws. The shareholder’s last known address of record determines which state has jurisdiction. Interest or income is not earned on redemption or distribution check(s) sent to you during the time the check(s) remained uncashed.

20 ï Janus Detroit Street Trust

You can make inquiries and request other information, including a Statement of Additional Information, annual report, or semiannual report (as they become available), free of charge, by contacting your plan sponsor, broker-dealer, or financial intermediary, or by contacting a Janus representative at 1-877-335-2687. The Fund’s Statement of Additional Information and most recent annual and semiannual reports are also available, free of charge, at janus.com/etfs. Additional information about the Fund’s investments is available in the Fund’s annual and semiannual reports. In the Fund’s annual and semiannual reports, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund’s performance during its last fiscal period. Other information is also available from financial intermediaries that sell shares of the Fund.

The Statement of Additional Information provides detailed information about the Fund and is incorporated into this Prospectus by reference. You may review and copy information about the Fund (including the Fund’s Statement of Additional Information) at the Public Reference Room of the SEC or get text only copies, after paying a duplicating fee, by sending an electronic request by e-mail to publicinfo@sec.gov or by writing to or calling the Commission’s Public Reference Section, Washington, D.C. 20549-1520 (1-202-551-8090). Information on the operation of the Public Reference Room may also be obtained by calling this number. You may also obtain reports and other information about the Fund from the Electronic Data Gathering Analysis and Retrieval (EDGAR) Database on the SEC’s website at http://www.sec.gov.

janus.com/etfs

151 Detroit Street

Denver, CO 80206-4805

1-877-335-2687

The Trust’s Investment Company Act File No. is 811-23112.

6 [ , 2016]

Subject to Completion

Preliminary Prospectus Dated February 18, 2016


		Ticker
Janus Small/Mid Cap Growth Alpha ETF		JSMD
Principal U.S. Listing Exchange: NASDAQ Stock Market, Inc.

Janus Detroit Street Trust

Prospectus

Fund summary

Janus Small/Mid Cap Growth Alpha ETF


Ticker:		JSMD

INVESTMENT OBJECTIVE

Janus Small/Mid Cap Growth Alpha ETF seeks investment results that correspond generally, before fees and expenses, to the performance of its underlying index, the Janus Small/Mid Cap Growth Alpha Index (the “Underlying Index”).

FEES AND EXPENSES OF THE FUND


ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Management Fees	0.50	%
Other Expenses⁽¹⁾	0.00	%
Total Annual Fund Operating Expenses	0.50	%


(1)	Other Expenses are based on the estimated expenses that the Fund expects to incur.

EXAMPLE:


1 Year		3 Years
$	51	$	160

PRINCIPAL INVESTMENT STRATEGIES

The Underlying Index, Janus Small/Mid Cap Growth Alpha Index, is composed of common stocks of small- and medium-sized companies that are selected by the index provider, Janus Index & Calculation Services LLC (“Janus Index Services” or the “Index Provider”), from those companies included in the Solactive Small/Mid Cap Index, a universe of 2,500 small- and medium-sized capitalization stocks. The Underlying Index is designed to select small- and medium-sized capitalization stocks that are poised for “smart growth” by evaluating each company’s performance in three critical areas: growth, profitability, and capital efficiency. The Index Provider scores such stocks based on fundamental measures of their growth, profitability, and capital efficiency, and selects the top 10% of such eligible stocks scoring the highest using a proprietary quantitative methodology. To arrive at the top 10%, for each security in the stated universe, the quantitative methodology assigns a score in each of 10 different fundamental factors, relative to other eligible securities. The fundamental factors include measures that Janus Capital believes are tied to a stock’s outperformance relative to other small/mid cap stocks, and indicate a company’s performance with respect to growth (such as the revenue growth rate over 2- 5- and 8- year periods), profitability (such as margin expansion, profit margin and earnings per share over time) and capital efficiency (such as returns on invested capital).

2 ï Janus Small/Mid Cap Growth Alpha ETF

The scores for each factor are then added together, with equal weighting, to arrive at an overall score. The stocks with the highest 10% of scores are then weighted within the Underlying Index according to their market capitalization. Finally, the stocks are sector-weighted to reflect the sector allocation weight of Janus Triton Fund, based on its most recent publicly available holdings. A stock may not represent more than 3% of the Underlying Index. The Underlying Index, Janus Small/Mid Cap Growth Alpha Index, seeks risk adjusted outperformance relative to a market capitalization weighted universe of small- and medium-sized capitalization growth stocks. Market capitalizations within the Underlying Index will vary, but as of January 29, 2016, they ranged from approximately $55 million to $15.8 billion. The Underlying Index is rebalanced on a quarterly basis based on the methodology described above.

The Fund uses a “passive,” index-based approach in seeking performance that corresponds to the performance of the Underlying Index. The Fund generally will use a replication methodology, meaning it will invest in the securities composing the Underlying Index, Janus Small/Mid Cap Growth Alpha Index, in proportion to the weightings in the Underlying Index. However, the Fund may utilize a sampling methodology under various circumstances in which it may not be possible or practicable to purchase all of the securities in the Underlying Index. Janus Capital expects that over time, if the Fund has sufficient assets, the correlation between the Fund’s performance, before fees and expenses, and that of the Underlying Index will be 95% or better. A figure of 100% would indicate perfect correlation.

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

The Fund’s returns and yields will vary, and you could lose money. The principal risks and special considerations associated with investing in the Fund are set forth below.

Market Risk. The value of the Fund’s portfolio may decrease if the value of an individual company or security, or multiple companies or securities, in the portfolio decreases. Further, regardless of how well individual companies or securities perform, the value of the Fund’s portfolio could also decrease if there are deteriorating economic or market conditions. It is important to understand that the value of your investment may fall, sometimes sharply, in response to changes in the market, and you could lose money. Market risk may affect a single issuer, industry, economic sector, or the market as a whole. The Underlying Index has exposure to the small- and medium-sized capitalization sector of the stock market, and therefore at times the Fund may underperform the overall stock market.

Small- and Mid-Sized Companies Risk. The Fund’s investments in securities issued by small- and mid-sized companies, which can include smaller, start-up companies offering emerging products or services, may involve greater risks than are customarily associated with larger, more established companies. Securities issued by small- and mid-sized companies tend to be more volatile and somewhat more speculative than securities issued by larger or more established companies and may underperform as compared to the securities of larger companies.

3 ï Janus Small/Mid Cap Growth Alpha ETF

Methodology and Model Risk. Neither the Fund nor Janus Capital can offer assurances that tracking the Underlying Index will maximize returns or minimize risk, or be appropriate for every investor seeking a particular risk profile. Underlying Index risks include, but are not limited to, the risk that the factors used to determine the components of the Underlying Index, as applied by the Index Provider in accordance with the Underlying Index methodology, might not select securities that individually, or in the aggregate, outperform the broader small- and medium-sized capitalization universe. In addition, the Underlying Index was designed based on historically relevant fundamental factors and may not provide risk-adjusted outperformance in the future.

4 ï Janus Small/Mid Cap Growth Alpha ETF

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

MANAGEMENT

Investment Adviser: Janus Capital Management LLC

Portfolio Managers: Benjamin Wang, CFA, is Co-Portfolio Manager of the Fund, which he has co-managed since February 2016. Scott M. Weiner, DPhil, is Co-Portfolio Manager of the Fund, which he has co-managed since February 2016.

PURCHASE AND SALE OF FUND SHARES

TAX INFORMATION

PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

5 ï Janus Small/Mid Cap Growth Alpha ETF

Additional information about the Fund

FEES AND EXPENSES


•	“Annual Fund Operating Expenses” are paid out of the Fund’s assets. You do not pay these fees directly but, as the Example in the Fund Summary shows, these costs are borne indirectly by all shareholders.

•	The “Management Fee” is the rate paid by the Fund to Janus Capital for providing certain services. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•	“Other Expenses”


	○	include taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, securities lending expenses, and extraordinary expenses (such as litigation and indemnification expenses).


	○	include acquired fund fees and expenses, which are indirect expenses the Fund may incur as a result of investing in shares of an underlying fund. “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. Such amounts are currently estimated to be less than 0.01%.


•	All expenses in the Fund’s “Fees and Expenses of the Fund” table are shown without the effect of expense offset arrangements. Pursuant to such arrangements, credits realized as a result of uninvested cash balances are used to reduce custodian and transfer agent expenses.

ADDITIONAL INVESTMENT STRATEGIES AND GENERAL PORTFOLIO POLICIES

Real Estate-Related Securities

6 ï Janus Detroit Street Trust

Securities Lending

Non-Index Investments

RISKS OF THE FUND

The value of your investment will vary over time, sometimes significantly, and you may lose money by investing in the Fund. The Fund invests substantially all of its assets in small- and medium-sized capitalization stocks. The following information is intended to help you better understand some of the risks of investing in the Fund. The impact of the following risks on the Fund may vary depending on the Fund’s investments. The greater the Fund’s investment in a particular security, the greater the Fund’s exposure to the risks associated with that security. Before investing in the Fund, you should consider carefully the risks that you assume when investing in the Fund.

7 ï Janus Detroit Street Trust

These risks are described further in the Statement of Additional Information.

INFORMATION REGARDING THE UNDERLYING INDEX

The Underlying Index is composed of common stocks that are selected by the Index Provider from a universe of 2,500 small-and medium-sized capitalization stocks. The Underlying Index is designed to select small- and medium-sized capitalization stocks which are poised for “smart growth” by evaluating each company’s performance in three critical areas: growth,

8 ï Janus Detroit Street Trust

profitability, and capital efficiency. The Index Provider scores such stocks based on fundamental measures of their growth, profitability, and capital efficiency, and selects the top 10% of such eligible stocks scoring the highest using a proprietary quantitative methodology. To arrive at the top 10%, for each security in the stated universe, the quantitative methodology assigns a score in each of 10 different factors, relative to other eligible securities. The fundamental factors include measures that Janus Capital believes are tied to a stock’s outperformance relative to other small/mid cap stocks, and indicate a company’s performance with respect to growth (such as the revenue growth rate over 2- 5- and 8- year periods), profitability (such as margin expansion, profit margin and earnings per share over time) and capital efficiency (such as returns on invested capital). An eligible security is given a decile score and may also receive additional points for exceeding an established threshold. Each stock in the eligible universe will receive a point total equal to the decile rank of the stock for a given factor. For example, if a stock is in the top decile for a given factor, it will receive 10 points for that factor. If the stock is in the lowest decile, it will receive 1 point. For each factor, a threshold is established, and to the extent a stock’s score within a factor meets or exceeds the threshold, it will receive additional points. A high threshold means that exceeding that threshold is relatively difficult for a stock to achieve, and as a result will receive more bonus points than if the threshold were lower. For detailed information on how stocks are scored, see the Janus Small/Mid Cap Growth Alpha Index Methodology document, available at the Index Provider’s website.

The scores for each factor are then added together, with equal weighting, to arrive at an overall score. These stocks are then weighted within the Underlying Index according to their market capitalization. Finally, the stocks are sector-weighted to reflect the sector allocation weight of Janus Triton Fund, based on its most recent publicly available holdings. A stock may not represent more than 3% of the Underlying Index. The Underlying Index seeks risk adjusted outperformance relative to a market capitalization weighted universe of small- and medium-sized capitalization growth stocks. Market capitalizations within the Underlying Index will vary, but as of January 29, 2016, they ranged from approximately $55 million to $15.8 billion. The Underlying Index is rebalanced on a quarterly basis based the methodology described above.

The Underlying Index is compiled and administered by Janus Index Services, an affiliate of the Fund and Janus Capital.

9 ï Janus Detroit Street Trust

Management of the Fund

INVESTMENT ADVISER

The Trustees and the initial shareholder of the Fund have approved the use of a manager-of-managers structure for the Fund.

MANAGEMENT EXPENSES

The Fund’s Management Fee is calculated daily and paid monthly. The Fund’s advisory agreement details the Management Fee and other expenses that the Fund must pay.

The following table reflects the Fund’s contractual Management Fee rate (expressed as an annual rate). The rate shown is a fixed rate based on the Fund’s average daily net assets.

10 ï Janus Detroit Street Trust

INVESTMENT PERSONNEL

Janus Small/Mid Cap Growth Alpha ETF

Information about the portfolio managers’ compensation structure and other accounts managed is included in the SAI.

Conflicts of Interest

11 ï Janus Detroit Street Trust

Other information

DISTRIBUTION OF THE FUND

INDEX PROVIDER

Disclaimers

Janus Index Services is the licensor of certain trademarks, service marks, and trade names.

12 ï Janus Detroit Street Trust

Dividends, distributions, and taxes

DISTRIBUTIONS

Distribution Schedule

How Distributions Affect the Fund’s NAV

TAXES

Taxes on Distributions

13 ï Janus Detroit Street Trust

Taxes on Sales

Taxation of the Fund

Dividends, interest, and some capital gains received by the Fund on foreign securities may be subject to foreign tax withholding or other foreign taxes.

14 ï Janus Detroit Street Trust

Shareholder’s guide

The Fund issues or redeems its shares at NAV per share only in Creation Units. Shares of the Fund are listed for trading on a national securities exchange and trade on the secondary market during the trading day. Shares can be bought and sold throughout the trading day like shares of other publicly traded companies. There is no minimum investment. When buying or selling Fund shares through a broker, you will incur customary brokerage commissions and charges, and you may pay some or all of the spread between the bid and offered price in the secondary market on each purchase and sale transaction. Fund shares are traded on the NASDAQ under the trading symbol JSMD. Share prices are reported in dollars and cents per share.

PRICING OF FUND SHARES

All purchases, sales, or other account activity must be processed through your financial intermediary or plan sponsor.

DISTRIBUTION AND SERVICING FEES

Distribution and Shareholder Servicing Plan

15 ï Janus Detroit Street Trust

PAYMENTS TO FINANCIAL INTERMEDIARIES BY JANUS CAPITAL OR ITS AFFILIATES

16 ï Janus Detroit Street Trust

preferred or recommended funds and/or the provision of preferential or enhanced opportunities to promote the Janus funds in various ways within such financial intermediary’s organization.

PURCHASING AND SELLING SHARES

Continuous Offering

17 ï Janus Detroit Street Trust

Book Entry

Share Prices

Premiums and Discounts

18 ï Janus Detroit Street Trust

Investments by Other Investment Companies

The Trust and the Fund are part of the Janus family of funds and are related for purposes of investor and investment services, as defined in Section 12(d)(1)(G) of the 1940 Act.

EXCESSIVE TRADING

AVAILABILITY OF PORTFOLIO HOLDINGS INFORMATION

For additional information on these disclosures and the availability of portfolio holdings information, please refer to the Fund’s SAI.

SHAREHOLDER COMMUNICATIONS

Statements and Reports

Your financial intermediary or plan sponsor is responsible for sending you periodic statements of all transactions, along with trade confirmations and tax reporting, as required by applicable law.

19 ï Janus Detroit Street Trust

Lost (Unclaimed/Abandoned) Accounts

20 ï Janus Detroit Street Trust

janus.com/etfs

151 Detroit Street

Denver, CO 80206-4805

1-877-335-2687

The Trust’s Investment Company Act File No. is 811-23112.

6 [ , 2016]

Subject to Completion

Preliminary Prospectus Dated February 18, 2016


		Ticker
Janus Velocity Tail Risk Hedged Large Cap ETF		TRSK
Principal U.S. Listing Exchange: NYSE Arca, Inc.

Janus Detroit Street Trust

Prospectus

Fund summary

Janus Velocity Tail Risk Hedged Large Cap ETF


Ticker:		TRSK

INVESTMENT OBJECTIVE

Janus Velocity Tail Risk Hedged Large Cap ETF seeks investment results that correspond generally, before fees and expenses, to the performance of its underlying index, the VelocityShares Tail Risk Hedged Large Cap Index (the “Underlying Index”).

FEES AND EXPENSES OF THE FUND


ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Management Fees							0.65%
Other Expenses⁽¹⁾							0.00%
Acquired Fund Fees and Expenses⁽²⁾							0.06%
Total Annual Fund Operating Expenses							0.71%


(1)	Other Expenses are based on the estimated expenses that the Fund expects to incur.
(2)	“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. Such amounts are estimated based on the annualized expenses that the Fund expects to incur in its initial fiscal year.

EXAMPLE:


1 Year		3 Years
$	73	$	277

PRINCIPAL INVESTMENT STRATEGIES

Janus Capital will seek investment results that correspond generally, before fees and expenses, to the performance of the VelocityShares Tail Risk Hedged Large Cap Index. The Underlying Index is an index comprised of three large capitalization equity ETFs and two volatility related ETFs (the “Underlying Index ETFs”). The Fund will seek to achieve its investment objective by investing at least 80% of its net assets (plus any borrowings for investment purposes) in Underlying Index ETFs. Under normal circumstances, the Fund intends to invest 85% of its net assets in ETFs that provide exposure to large

2 ï Janus Velocity Tail Risk Hedged Large Cap ETF

capitalization securities, and 15% of its net assets to a volatility strategy. The volatility strategy will generally invest in swap agreements or other derivatives instead of investing directly in certain Underlying Index ETFs, as described below.

The Underlying Index and its Allocation

The Underlying Index reflects the performance of a portfolio providing exposure to:

(1) A large cap equity portfolio, consisting of the three Underlying Index ETFs listed below, which track the Standard & Poor’s 500^® Index (the “S&P 500^® Index,” with the Underlying Index ETFs tracking the S&P 500^® Index being the “Underlying Large Cap ETFs”); and

(2) A volatility strategy to hedge “tail risk” events (which are market events that occur rarely but may result in severe negative market performance when they do occur) in the S&P 500^® Index, consisting of the two Underlying Index ETFs listed below which utilize futures contracts, swap agreements, and other financial investments to gain leveraged or inverse positions on the S&P 500 VIX Short-Term Futures Index (the “Short-Term VIX Futures” with such Underlying Index ETFs being the “Underlying Volatility ETFs”). The “VIX” refers to the Chicago Board Options Exchange, Incorporated Volatility Index. The VIX is designed to measure the market’s expectation of 30-day volatility in the S&P 500. The Short-Term VIX Futures measures the movements of a combination of VIX futures contracts and is designed to track changes in the expected volatility of the S&P 500 one month in the future. In other words, the volatility strategy seeks to hedge against “tail risk” events, to the extent such events and/or the market reaction to such events are reflected in the prices of VIX futures.

The Underlying Index consists of an 85% allocation to the Underlying Large Cap ETFs (split evenly between each Underlying Large Cap ETF) and a 15% allocation to the Underlying Volatility ETFs (such allocation being the “Volatility Component”). The Underlying Index is rebalanced monthly to reset the allocations to the Underlying Large Cap ETFs and the Volatility Component to 85% and 15%, respectively. The Underlying Index’s allocation between Underlying Index ETFs is designed to reflect the performance of the S&P 500^® Index while also providing a hedging exposure against “tail risk” events on the S&P 500^® Index.

The Underlying Index ETFs included in the Underlying Index and their investment exposure are set forth below:

Underlying Index ETFs


				Investment exposure
		Ticker	Underlying	(before fees and
Name	Investment Adviser	Symbol	Index	expenses)
Underlying Large Cap ETFs

SPDR S&P 500 ETF Trust	PDR Services, LLC, as Sponsor of the Trust (“Sponsor”), and State Street Bank and Trust Company, as Trustee of the Trust (“Trustee”)	SPY	S&P 500^® Index	Tracking of S&P 500^® Index

Vanguard S&P 500 ETF	The Vanguard Group, Inc.	VOO	S&P 500^® Index	Tracking of S&P 500^® Index

iShares Core S&P 500 ETF	BlackRock Fund Advisors	IVV	S&P 500^® Index	Tracking of S&P 500^® Index

Underlying Volatility ETFs

Ultra VIX Short-Term Futures ETF (the “Ultra Fund”)	ProShare Capital Management LLC	UVXY	S&P 500 VIX Short-Term Futures Index	Twice the return of Short-Term VIX Futures on a daily basis

Short VIX Short-Term Futures ETF (the “Short Fund”)	ProShare Capital Management LLC	SVXY	S&P 500 VIX Short-Term Futures Index	Inverse of the return of Short-Term VIX Futures on a daily basis

The Underlying Index allocates the Volatility Component to a target weight between the Underlying Volatility ETFs as follows:


Index	Target Allocation	Target Net Allocation
VelocityShares Tail Risk Hedged Large Cap Index	45% (Ultra Fund, with 2x exposure), 55% (Short Fund, with -1x exposure)	35% long

3 ï Janus Velocity Tail Risk Hedged Large Cap ETF

The Volatility Component portion of the Underlying Index is rebalanced in a gradual manner over each quarter to preserve this allocation. This allocation results in a target net 35% long exposure to the Short-Term VIX Futures, although market movement in VIX futures will result in allocations on any given day that differ, sometimes significantly from the target exposure, including the potential for net short exposure. The Volatility Component is structured in a manner intended to benefit from significant, sustained movements, over multiple trading days, in either direction by Short-Term VIX Futures, but will likely benefit more from a multi-day significant, sustained upward movement than a multi-day significant, sustained downward movement.

The Underlying Volatility ETFs are not registered as investment companies under the Investment Company Act of 1940, as amended (the “1940 Act”). The Underlying Volatility ETFs are sponsored by a registered commodity pool operator and advised by a registered commodity trading adviser.

How the Fund Attempts to Replicate the Underlying Index

The Fund will attempt to correspond generally, before fees and expenses, to the performance of the Underlying Index by investing under normal circumstances in (a) shares of the Underlying Large Cap ETFs and (b) one or more swaps designed to replicate the performance of the volatility component directly by reference to closing prices of the underlying VIX futures. The Fund could also elect to trade VIX futures directly, although the Fund does not expect to use such instruments under normal circumstances. The Fund may also invest directly in shares of the Underlying Volatility ETFs, though it does not currently intend to do so. While the Underlying Volatility ETFs utilize futures contracts, swap agreements and other financial instruments, the Fund’s only direct use of such instruments will be solely as described in (b) above.

The Underlying Index is compiled and administered by Janus Index & Calculation Services LLC (“Janus Index Services” or the “Index Provider”). Janus Index Services is affiliated with the Fund and Janus Capital.

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. The principal risks and special considerations associated with investing in the Fund are set forth below.

Fund of Funds Risk. The Fund pursues its investment objective by investing its assets in the Underlying Large Cap ETFs and swaps linked to the performance of the Underlying Volatility ETFs rather than investing directly in stocks, bonds, cash or other investments. The Fund’s investment performance thus depends on the investment performance of the Underlying Index ETFs in which it invests. An investment in the Fund therefore is subject to the risks associated with the Underlying Index ETFs that comprise the Underlying Index. The Fund will indirectly pay a proportional share of the asset-based fees of the Underlying Index ETFs in which it invests.

Underlying Index ETFs Risks. Investment in the Underlying Index ETFs may subject the Fund to the following risks: Market Risk; Stock Market Risk; Equity Investing Risk; Investment Style Risk; Non-Correlation Risk; and Large Capitalization Company Risk. The Fund may also be subject to certain other risks specific to the Underlying Volatility ETFs which are set forth below.

Market Risk. The Fund’s investment in an Underlying Index ETF involves risks similar to those of investing in any fund of equity securities, such as market fluctuations caused by such factors as economic and political developments, changes in interest rates and perceived trends in stock prices. The values of equity securities could decline generally or could underperform other investments. Different types of equity securities tend to go through cycles of out-performance and under-performance in comparison to the general securities markets. In addition, securities may decline in value due to factors affecting a specific issuer, market or securities markets generally.

Stock Market Risk. Stock prices overall may decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Underlying Index has a large exposure to the large capitalization sector of the stock market and an exposure to a volatility strategy, therefore at times the Fund may underperform the overall stock market.

Equity Investing Risk. The Fund’s investment in the Underlying Index ETFs involves risks similar to those of investing in any fund of equity securities, such as market fluctuations, changes in interest rates and perceived trends in stock prices.

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general. These cycles may continue for extended periods of time. In addition, the Volatility Component may not be successful in hedging against market volatility at any time.

Non-Correlation Risk. The Fund’s return may not match the return of the Underlying Index for a number of reasons. For example, the Fund incurs a number of operating expenses not applicable to the Underlying Index, and incurs costs in buying and selling securities, especially when rebalancing the Fund’s Underlying ETF holdings (and swaps or other instruments designed to provide exposure to the Volatility Component) to reflect changes in the composition of the Underlying Index. In addition, the 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 resulting from legal restrictions, cash flows or operational inefficiencies. Finally, the Fund intends to obtain exposure to the Volatility Component through swaps or other derivative instruments rather than holding shares of the Underlying Volatility ETFs directly, and thus the Fund may experience additional tracking error if the return of such derivatives differs from that of the Underlying Volatility ETFs.

Due to legal and regulatory rules and limitations, the Fund may be limited in its ability to invest in all securities included in the Underlying Index. For tax efficiency purposes, the Fund may sell certain securities to realize losses, causing it to deviate from the Underlying Index.

The 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 expenses. If the Fund utilizes a sampling approach or otherwise does not hold all of the securities in the Underlying Index, its return may not correlate as well with the return on the Underlying Index, as would be the case if it purchased all of the securities in the Underlying Index with the same weightings as the Underlying Index.

Large Capitalization Company Risk. The large capitalization companies in which the Underlying Index ETFs may invest may fall out of favor with investors based on market and economic conditions. In return for the relative stability and low volatility of large capitalization companies, an Underlying Index ETF’s value may not rise as much as the value of funds that focus on companies with smaller market capitalizations.

Swap Risk. The Fund expects to use cleared and over-the-counter (“OTC”) swap agreements in addition to other derivatives to obtain exposure to the Underlying Volatility ETFs and/or the VIX Short-Term Futures Index as a means to achieve its investment objective. An OTC swap contract is an agreement between two parties pursuant to which the parties exchange payments at specified dates on the basis of a specified notional amount, with the payments calculated by reference to specified securities, indices, reference rates, currencies or other instruments. Typically swap agreements provide that when the period payment dates for both parties are the same, the payments are made on a net basis (i.e., the two payment streams are netted out, with only the net amount paid by one party to the other). The Fund’s obligations or rights under a swap contract entered into on a net basis will generally be equal only to the net amount to be paid or received under the agreement, based on the relative values of the positions held by each party. Cleared swap transactions may help reduce counterparty credit risk. In a cleared swap, the Fund’s ultimate counterparty is a clearinghouse rather than a bank, dealer or financial institution. OTC swap agreements are not entered into or traded on exchanges and often there is no central clearing or guaranty function for swaps. These OTC swaps are often subject to credit risk or the risk of default or non-performance by the counterparty. Both OTC and cleared swaps could result in losses if interest rates or credit quality changes are not correctly anticipated by the Fund or if the reference index, security or investments do not perform as expected. The Dodd-Frank Wall Street Reform and Consumer Protection Act and related regulatory developments require the clearing and exchange-trading of certain standardized swap transactions. Mandatory exchange-trading and clearing is occurring on a phased-in basis.

If the Volatility Component has a dramatic intraday move in value that would cause a material decline in the Fund’s NAV, the terms of the swap may permit the counterparty to immediately close out the transaction with the Fund. In that event, it may not be possible for the Fund to enter into another swap agreement or to invest in other instruments necessary to achieve the desired exposure to the Underlying Volatility ETFs consistent with the Fund’s investment objective. This, in turn, may prevent the Fund from achieving its investment objective, even if the value of the Fund’s benchmark reverses all or part of its intraday move by the end of the day.

The Fund may be charged a fee by the counterparty or clearinghouse in connection with entering into a swap transaction. Similar to other portfolio transaction fees, the cost of investing in swaps is an indirect expense of the Fund that is not included in the Fee Table.

Compounding Risk. Each of the Underlying Volatility ETFs has an investment objective to match (before fees and expenses) a multiple (i.e., 2x in the case of the Ultra Fund) or the inverse (i.e., -1x in the case of the Short Fund) of the performance of the

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Short-Term VIX Futures on a given day. Each Underlying Volatility ETF seeks investment results for a single day only, and not for any other period. The return of an Underlying Volatility ETF for a period longer than a day is the result of its return for each day compounded over the period and usually will differ from twice (2x) or the inverse (-1x) of the return of the Fund’s index for the period. An Underlying Volatility ETF will lose money if the Short-Term VIX Futures performance is flat over time, and it is possible for an Underlying Volatility ETF to lose money over time even if the Short-Term VIX Futures’ performance increases (or decreases in the case of the Short Fund), as a result of daily rebalancing, the Short-Term VIX Futures’ volatility and compounding. Longer holding periods, higher index volatility and greater leverage each affect the impact of compounding on an Underlying Volatility ETF’s returns. Daily compounding of an Underlying Volatility ETF’s investment returns can dramatically and adversely affect its longer-term performance during periods of high volatility. Volatility may be at least as important to an Underlying Volatility ETF’s return for a period as the return of the Short-Term VIX Futures. The Underlying Volatility ETFs are not appropriate for direct investments for all investors and present different risks than most mutual funds.

However, the Fund’s exposures to the performance of the Underlying Volatility ETFs are part of a hedging strategy intended to reduce the risk of substantial declines in the S&P 500 due to a tail event. The Fund’s exposures to the performance of the Underlying Volatility ETFs (i) only represent up to 20% of the Fund’s portfolio, (ii) are comprised of partially offsetting holdings of leveraged and inverse positions on the Short-Term VIX Futures with a target net allocation of a 35% long position designed to minimize the effects of compounding in either a positive or negative direction, and (iii) are frequently rebalanced in a gradual manner to generally maintain a 15% allocation to the Volatility Component and the target net allocation of the Volatility Component’s overall exposure. Therefore, in the context of the Fund’s overall portfolio, the Fund’s investments in the Underlying Volatility ETFs present significantly different risks to an investor than a direct investment in an Underlying Volatility ETF.

Risk of Leveraged and Inverse Investment. The Ultra Fund utilizes leverage and the Short Fund utilizes inverse positions with respect to their respective indices. Accordingly, a substantial movement in the underlying index of an Underlying Volatility ETF in the opposite direction of the Underlying Volatility ETF’s position (e.g., a downward movement with respect to a leveraged position and an upward movement with respect to an inverse position) may result in a substantial loss of the Fund’s investment exposure to such Underlying Volatility ETF, up to the complete amount of the Fund’s investment. While the Fund’s exposures to Underlying Volatility ETFs and/or the Short-Term VIX Futures directly, are intended to balance each other out to an extent (as one Underlying Volatility ETF and/or swap entered into by the Fund takes a leveraged position with respect to the Short-Term VIX Futures while the other takes a short position), there is no guarantee that the offsetting positions of the Fund’s swaps and/or the Underlying Volatility ETFs will prevent the Fund from suffering losses. While the Underlying Index’s, and thus the Fund’s, target net allocation to the Short-Term VIX Futures is 35% long (and the Volatility Component is regularly rebalanced to preserve this target net allocation), the Fund’s net exposure to volatility will vary on any given day, sometimes significantly from the target net allocation, and could result in a net short position due to daily decreases in VIX Futures prices. In such circumstances, the Fund could experience losses in its exposure to Underlying Volatility ETFs in the event of any increase in the underlying index of the Underlying Volatility ETF.

Liquidity Risk. Market illiquidity may cause losses for the swaps entered into by the Fund and/or the Underlying Volatility ETFs. The large size of the positions which the Underlying Volatility ETFs may acquire increases the risk of illiquidity by both making their positions more difficult to liquidate and increasing the losses incurred while trying to do so. Any type of disruption or illiquidity will potentially be exacerbated due to the fact that the Underlying Volatility ETFs will typically invest in financial instruments related to one benchmark (the Short-Term VIX Futures), which in many cases is highly concentrated. The swaps entered into by the Fund on the Underlying Volatility ETFs and/or the Short-Term VIX Futures directly may reflect these risks as well.

Nondiversification Risk. The Fund is classified as nondiversified under the 1940 Act. This gives the Fund more flexibility to hold larger positions in a smaller number of securities. As a result, an increase or decrease in the value of a single security held by the Fund may have a greater impact on the Fund’s net asset value and total return.

Cash Redemption Risk. Because the Fund invests a portion of its assets in swaps, the Fund may pay out a portion of its redemption proceeds in cash rather than through the in-kind delivery of portfolio securities. The Fund may be required to unwind such contracts or sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. This may cause the Fund to recognize a capital gain that it might not have incurred if it had made a redemption in-kind. As a result, the Fund may pay out higher annual capital gains distributions than if the in-kind redemption process was used.

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fluctuate in accordance with changes in NAV as well as the relative supply of, and demand for, the Underlying Index ETF shares on the applicable listing exchange. The Underlying Index ETF shares may thus trade below, at or above their NAV. If the Fund purchases shares at a time when the market price is at a premium to the NAV of the shares or sells at a time when the market price is at a discount to the NAV of the shares, then the Fund may sustain losses. Price differences may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for the Underlying Index ETF shares will be closely related to, but not identical to, the same forces influencing the prices of the stocks and/or financial instruments individually or in the aggregate at any point in time by an Underlying Index ETF.

Trading Issues Risk. Trading in shares on NYSE Arca may be halted due to market conditions or for reasons that, in the view of NYSE Arca, make trading in shares inadvisable. In addition, trading in shares on NYSE Arca is subject to trading halts caused by extraordinary market volatility pursuant to NYSE Arca “circuit breaker” rules. There can be no assurance that the requirements of NYSE Arca necessary to maintain the listing of the Fund will continue to be met or will remain unchanged.

While the creation/redemption feature is designed to make it likely that shares will trade close to the Fund’s NAV, disruptions to creations and redemptions, may result in trading prices that differ significantly from the Fund’s NAV. An absence of trading in shares of the Fund, or a high volume of trading in the Fund, may also result in trading prices that differ significantly from the Fund’s NAV. If an investor purchases shares at a time when the market price is at a premium to the NAV of the shares or sells at a time when the market price is at a discount to the NAV of the shares, then the investor may sustain losses.

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

MANAGEMENT

Investment Adviser: Janus Capital Management LLC

PURCHASE AND SALE OF FUND SHARES

Unlike shares of traditional mutual funds, shares of the Fund are not individually redeemable and may only be purchased or redeemed directly from the Fund at net asset value (“NAV”) in large increments called “Creation Units” (50,000 or more shares per Creation Unit) through certain participants, known as “Authorized Participants.” The Fund will issue or redeem Creation Units in exchange for portfolio securities included in the Fund’s Underlying Index and/or cash. Because the Fund uses swap instruments, which require cash to establish, maintain and settle transactions, and cannot be readily transferred, the Fund will need to issue and redeem Creation Units partially for cash under normal circumstances. Except when aggregated in Creation Units, Fund shares are not redeemable securities of the Fund.

Shares of the Fund are listed and trade on NYSE Arca, Inc. (“NYSE Arca”), and individual investors can purchase or sell shares in much smaller increments and for cash in the secondary market through a broker. These transactions, which do not involve the Fund, are made at market prices that may vary throughout the day and differ from the Fund’s net asset value. As a result, you may pay more than net asset value (at a premium) when you purchase shares, and receive less than net asset value (at a discount) when you sell shares, in the secondary market.

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Additional information about the Fund

FEES AND EXPENSES


•	“Annual Fund Operating Expenses” are paid out of the Fund’s assets. You do not pay these fees directly but, as the Example in the Fund Summary shows, these costs are borne indirectly by all shareholders.

•	The “Management Fee” is the rate paid by the Fund to Janus Capital for providing certain services. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•	“Other Expenses” include taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, securities lending expenses, and extraordinary expenses (such as litigation and indemnification expenses).


•	All expenses in the Fund’s “Fees and Expenses of the Fund” table are shown without the effect of expense offset arrangements. Pursuant to such arrangements, credits realized as a result of uninvested cash balances are used to reduce custodian and transfer agent expenses.

ADDITIONAL INVESTMENT STRATEGIES AND GENERAL PORTFOLIO POLICIES

Although the Fund will invest at least 80% of its net assets in Underlying Index ETFs and up to 20% of its net assets in derivative instruments, the Fund may invest its remaining assets in money market instruments, including repurchase agreements or other funds which invest exclusively in money market instruments. Options and futures contracts (and convertible securities and structured notes) may be used by the Fund in seeking performance that corresponds to its Underlying Index. The Fund will not invest in money market instruments as part of a temporary defensive strategy to protect against potential stock market declines generally, or declines in the Underlying Index specifically. Janus Capital anticipates that it may take approximately three business days (i.e., each day the NYSE is open) for additions and deletions to the Underlying Index to be reflected in the portfolio composition of the Fund.

The Fund may borrow money from a bank up to a limit of 10% of the value of its assets, but only for temporary or emergency purposes.

Nondiversification

Diversification is a way to reduce risk by investing in a broad range of stocks or other securities. The Fund is classified as “nondiversified.” A fund that is classified as “nondiversified” has the ability to take larger positions in a smaller number of

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issuers than a fund that is classified as “diversified.” Because the appreciation or depreciation of a single security may have a greater impact on the net asset value of a fund which is classified as nondiversified, its share price can be expected to fluctuate more than a comparable fund which is classified as diversified. This fluctuation, if significant, may affect the performance of the fund.

Securities Lending

RISKS OF THE FUND

The value of your investment will vary over time, sometimes significantly, and you may lose money by investing in the Fund. The Fund invests substantially all of its assets in Underlying Index ETFs. The following information is intended to help you better understand some of the risks of investing in the Fund. The impact of the following risks on the Fund may vary depending on the Fund’s investments. The greater the Fund’s investment in a particular security, the greater the Fund’s exposure to the risks associated with that security. Before investing in the Fund, you should consider carefully the risks that you assume when investing in the Fund.

Derivatives Risk. The Fund may invest in derivatives. Derivatives can be highly volatile and involve risks in addition to the risks of the underlying referenced securities. 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.

While the creation/redemption feature is designed to make it likely that shares will trade close to the Fund’s NAV, disruptions to creations and redemptions may result in trading prices that differ significantly from the Fund’s NAV. An absence of trading in shares of the Fund, or a high volume of trading in the Fund, may also result in trading prices that differ significantly from the Fund’s NAV. If an investor purchases shares at a time when the market price is at a premium to the NAV of the shares or sells at a time when the market price is at a discount to the NAV of the shares, then the investor may sustain losses.

Tax Risk Related to Commodity Pool Investments. While the Fund currently intends to obtain exposure to the Volatility Component through swaps or other derivatives rather than holding Underlying Volatility ETFs directly, the Fund may in the future invest directly in Underlying Volatility ETFs. Such Underlying Volatility ETFs are treated as “qualified publicly traded

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partnerships” or grantor trusts for federal income tax purposes. Investments by the Fund in “qualified publicly traded partnerships” and grantor trusts must be monitored and limited so as to enable the Fund to satisfy certain asset diversification and qualifying income tests for qualification as a regulated investment company (a “RIC”) under Subchapter M of the Internal Revenue Code. Failure to satisfy either test would jeopardize the Fund’s status as a RIC, which could result in adverse consequences to the Fund.

Securities Lending Risk. Although not considered a principal 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.

These risks are described further in the Statement of Additional Information.

INFORMATION REGARDING THE UNDERLYING INDEX

The Underlying Index and its Allocations

The VelocityShares Tail Risk Hedged Large Cap Index reflects the performance of a portfolio consisting of an exposure to (1) a large cap equity portfolio, consisting of the three Underlying Index ETFs listed below which track the Standard & Poor’s 500^® Index (the “S&P 500^® Index,” with the Underlying Index ETFs tracking the S&P 500^® Index being the “Underlying Large Cap ETFs”) and (2) a volatility strategy to hedge “tail risk” events (which are market events that occur rarely but may result in severe negative market performance when they do occur), consisting of the two Underlying Index ETFs listed below which utilize futures contracts, swap agreements and other financial investments to gain leveraged or inverse positions on the S&P 500 VIX (Chicago Board Options Exchange, Incorporated Volatility Index (the “VIX”)) Short-Term Futures Index (the “Short-Term VIX Futures;” with such Underlying Index ETFs being the “Underlying Volatility ETFs”).

The Underlying Index consists of an 85% allocation to the Underlying Large Cap ETFs (split evenly between each Underlying Large Cap ETF) and a 15% allocation to the Underlying Volatility ETFs (the “Volatility Component”). The Volatility Component in the Underlying Index seeks to replicate long/short exposure to short-dated VIX futures, with a targeted net long exposure of 35% as set forth in the table below under “Index Description.”

The Underlying Volatility ETFs are not registered as investment companies under the 1940 Act. The Underlying Volatility ETFs are sponsored by a registered commodity pool operator and advised by a registered commodity trading adviser.

How the Fund Attempts to Replicate its Underlying Index

The Fund will attempt to correspond generally, before fees and expenses, to the performance of the Underlying Index by investing under normal circumstances in (a) shares of the Underlying Large Cap ETFs and (b) one or more derivative instruments (primarily swaps), designed to replicate the performance of the volatility component directly by reference to closing prices of the underlying VIX futures. The Fund could also elect to trade VIX futures directly, although the Fund does not expect to use such instruments under normal circumstances. The Fund may also invest directly in shares of the Underlying Volatility ETFs, though the Fund does not currently intend to do so. While the Underlying Volatility ETFs utilize futures contracts, swap agreements and other financial instruments, the Fund’s only direct use of such instruments will be solely as described in (b) above.

The Underlying Volatility ETFs intend to track the performance of their reference index (the Short-Term VIX Futures) on a daily basis. As a result, the returns of the Underlying Volatility ETFs over longer holding periods are generally lower than they would be for an ETF which attempted to track the performance of the Short-Term VIX Futures over longer holding periods. This effect tends to be most pronounced when the Short-Term VIX Futures is itself highly volatile, but does not experience a significant, sustained upward or downward trend over multiple trading days. The effect will be far smaller, or not exist at all, if the Short-Term VIX Futures experiences significant sustained movements and/or lower volatility. In fact, in those scenarios, the effect may reverse, and the Underlying Volatility ETFs may have better performance than an ETF which attempts to track the Short-Term VIX Futures over longer holding periods. The Volatility Component is intended to profit from these significant and sustained movements in the Short-Term VIX Futures, but similar to the Underlying Volatility ETFs, the returns of the Volatility Component within the Fund will be lower, compared to a long only position in the Short-Term

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VIX Futures, when the Short-Term VIX Futures is itself highly volatile and does not have significant sustained movement in any direction.

Index Description. The Underlying Index’s volatility allocation will be divided into 13 separate portions (each, a “sub-portfolio”), each reflecting a position in the Ultra VIX Short-Term Futures ETF (“Ultra Fund”) with a two-times (2X) leveraged exposure to Short-Term VIX Futures and the Short VIX Short-Term Futures ETF (“Short Fund”) with an inverse (-1X) exposure to the same short-term VIX futures index. The target allocation between the leveraged and inverse exposures for the volatility strategy for the Underlying Index is presented in the following table:

Volatility Strategy Target Allocation


Index	Target Allocation	Target Net Allocation
VelocityShares Tail Risk Hedged Large Cap Index	45% (Ultra Fund, with 2x exposure), 55% (Short Fund, with -1x exposure)	35% long

On a weekly basis, the exposures of one of the 13 sub-portfolios is rebalanced to its target allocation, such that during a quarter each of the sub-portfolios is rebalanced.

On a monthly basis, the Underlying Index’s overall portfolio is rebalanced such that the large cap equity market positions represent 85% of the portfolio value and the Volatility Component represents 15% of the portfolio value.

On a quarterly basis, the Underlying Index’s exposures to the three large-cap ETFs will be rebalanced such that each will have an equal weighting and the Underlying Index’s exposures to the 13 volatility strategy sub-portfolios will be rebalanced such that each sub-portfolio has an equal weighting.

The Underlying Index ETFs which currently constitute the Underlying Index are set forth in the table below:

Underlying Index ETFs


				Investment exposure
		Ticker	Underlying	(before fees and
Name	Investment Adviser	Symbol	Index	expenses)
Underlying Large Cap ETFs

SPDR S&P 500 ETF Trust	PDR Services, LLC, as Sponsor of the Trust (“Sponsor”), and State Street Bank and Trust Company, as Trustee of the Trust (“Trustee”)	SPY	S&P 500 Index	Tracking of S&P 500 Index

Vanguard S&P 500 ETF	The Vanguard Group, Inc.	VOO	S&P 500 Index	Tracking of S&P 500 Index

iShares Core S&P 500 ETF	BlackRock Fund Advisors	IVV	S&P 500 Index	Tracking of S&P 500 Index

Underlying Volatility ETFs

Ultra VIX Short-Term Futures ETF (the “Ultra Fund”)	ProShare Capital Management LLC	UVXY	S&P 500 VIX Short-Term Futures Index	Twice the return of Short-Term VIX Futures on a daily basis

Short VIX Short-Term Futures ETF (the “Short Fund”)	ProShare Capital Management LLC	SVXY	S&P 500 VIX Short-Term Futures Index	Inverse of the return of Short-Term VIX Futures on a daily basis

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Management of the Fund

INVESTMENT ADVISER

The Trustees and the initial shareholder of the Fund have approved the use of a manager-of-managers structure for the Fund.

MANAGEMENT EXPENSES

The Fund’s investment advisory fee is calculated daily and paid monthly. The Fund’s advisory agreement details the investment advisory fee and other expenses that the Fund must pay.

The following table reflects the Fund’s contractual Management Fee rate (expressed as an annual rate). The rate shown is a fixed rate based on the Fund’s average daily net assets.


	Average Daily		Contractual
	Net Assets		Management Fee (%)
Fund Name	of the Fund		(annual rate)
Janus Velocity Tail Risk Hedged Large Cap ETF		All Asset Levels		0.65

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INVESTMENT PERSONNEL

Janus Velocity Tail Risk Hedged Large Cap ETF

Information about the portfolio managers’ compensation structure and other accounts managed is included in the SAI.

Conflicts of Interest

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Other information

DISTRIBUTION OF THE FUND

INDEX PROVIDER

Janus Index & Calculation Services LLC (“Janus Index Services”) is the Index Provider for the Underlying Index. Janus Capital has entered into a license agreement with Janus Index Services to use the Underlying Index. Janus Index Services is affiliated with the Fund and Janus Capital. This affiliation may create potential conflicts for Janus Index Services as it may have an interest in the performance of the Fund, which could motivate it to alter the index methodology for the Underlying Index. Janus Index Services has adopted procedures that it believes are reasonably designed to mitigate these and other potential conflicts.

Disclaimers

Janus Index Services is the licensor of certain trademarks, service marks, and trade names.

Neither Janus Index Services nor any of its affiliates make any representation or warranty, express or implied, to the owners of the Fund or any member of the public regarding the advisability of investing in securities generally or in the Fund particularly or the ability of the Underlying Index to track general market performance. The Underlying Index is determined, composed, and calculated by Janus Index Services without regard to Janus Capital or the Fund. Janus Index Services has no obligation to take the needs of Janus Capital or the owners of the Fund into consideration in determining, composing, or calculating the Index. Janus Index Services is not responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Fund to be issued or in the determination or calculation of the equation by which the Fund is to be converted into cash.

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Dividends, distributions, and taxes

DISTRIBUTIONS

Distribution Schedule

How Distributions Affect the Fund’s NAV

TAXES

Taxes on Distributions

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Taxes on Sales

Taxation of the Fund

Dividends, interest, and some capital gains received by the Fund on foreign securities may be subject to foreign tax withholding or other foreign taxes.

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Shareholder’s guide

The Fund issues or redeems its shares at NAV per share only in Creation Units. Shares of the Fund are listed for trading on a national securities exchange and trade on the secondary market during the trading day. Shares can be bought and sold throughout the trading day like shares of other publicly traded companies. There is no minimum investment. When buying or selling Fund shares through a broker, you will incur customary brokerage commissions and charges, and you may pay some or all of the spread between the bid and offered price in the secondary market on each purchase and sale transaction. Fund shares are traded on NYSE Arca under the trading symbol TRSK. Share prices are reported in dollars and cents per share.

PRICING OF FUND SHARES

All purchases, sales, or other account activity must be processed through your financial intermediary or plan sponsor.

DISTRIBUTION AND SERVICING FEES

Distribution and Shareholder Servicing Plan

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PAYMENTS TO FINANCIAL INTERMEDIARIES BY JANUS CAPITAL OR ITS AFFILIATES

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preferred or recommended funds and/or the provision of preferential or enhanced opportunities to promote the Janus funds in various ways within such financial intermediary’s organization.

PURCHASING AND SELLING SHARES

The 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 Fund 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, the Fund may require orders to create or redeem Creation Units to be placed earlier in the day. See the Statement of Additional Information for more information.

Continuous Offering

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Book Entry

Share Prices

Premiums and Discounts

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Investments by Other Investment Companies

The Trust and the Fund are part of the Janus family of funds and are related for purposes of investor and investment services, as defined in Section 12(d)(1)(G) of the 1940 Act.

EXCESSIVE TRADING

AVAILABILITY OF PORTFOLIO HOLDINGS INFORMATION

Each business day, the Fund’s portfolio holdings information is provided to the Distributor or other agent for dissemination through the facilities of the NSCC and/or other fee-based subscription services to NSCC members and/or subscribers to entities that publish and/or analyze such information in connection with the process of purchasing or redeeming Creation Units or trading shares of the Fund in the secondary market. In addition, on each business day before commencement of trading in shares on the NYSE Arca, the Fund will disclose on janus.com/etfs the identities and quantities of each portfolio position held by the Fund that will form the basis for the Fund’s calculation of the NAV per share at the end of the business day. The Fund is also required to disclose its complete holdings in the quarterly holdings report on Form N-Q within 60 days of the end of the first and third fiscal quarters, and in the annual report and semiannual report to Fund shareholders.

For additional information on these disclosures and the availability of portfolio holdings information, please refer to the Fund’s SAI.

SHAREHOLDER COMMUNICATIONS

Statements and Reports

Your financial intermediary or plan sponsor is responsible for sending you periodic statements of all transactions, along with trade confirmations and tax reporting, as required by applicable law.

22 ï Janus Detroit Street Trust

Lost (Unclaimed/Abandoned) Accounts

23 ï Janus Detroit Street Trust

janus.com/etfs

151 Detroit Street

Denver, CO 80206-4805

1-877-335-2687

The Trust’s Investment Company Act File No. is 811-23112.

6 [ , 2016]

Subject to Completion

Preliminary Prospectus Dated February 18, 2016


		Ticker
Janus Velocity Volatility Hedged Large Cap ETF		SPXH
Principal U.S. Listing Exchange: NYSE Arca, Inc.

Janus Detroit Street Trust

Prospectus

Fund summary

Janus Velocity Volatility Hedged Large Cap ETF


Ticker:		SPXH

INVESTMENT OBJECTIVE

Janus Velocity Volatility Hedged Large Cap ETF seeks investment results that correspond generally, before fees and expenses, to the performance of its underlying index, the VelocityShares Volatility Hedged Large Cap Index (the “Underlying Index”).

FEES AND EXPENSES OF THE FUND


ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Management Fees			0.65%
Other Expenses⁽¹⁾			0.00%
Acquired Fund Fees and Expenses⁽²⁾			0.06%
Total Annual Fund Operating Expenses			0.71%


(1)	Other Expenses are based on the estimated expenses that the Fund expects to incur.
(2)	“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. Such amounts are estimated based on the annualized expenses that the Fund expects to incur in its initial fiscal year.

EXAMPLE:


1 Year		3 Years
$	73	$	277

PRINCIPAL INVESTMENT STRATEGIES

Janus Capital will seek investment results that correspond generally, before fees and expenses, to the performance of the VelocityShares Volatility Hedged Large Cap Index. The Underlying Index is an index comprised of three large capitalization equity ETFs and two volatility related ETFs (the “Underlying Index ETFs”). The Fund will seek to achieve its investment objective by investing at least 80% of its net assets (plus any borrowings for investment purposes) in Underlying Index ETFs. Under normal circumstances, the Fund intends to invest 85% of its net assets in ETFs that provide exposure to large

2 ï Janus Velocity Volatility Hedged Large Cap ETF

The Underlying Index and its Allocation

The Underlying Index reflects the performance of a portfolio providing exposure to:

(2) A volatility strategy to hedge “tail risk” events (which are market events that occur rarely but may result in severe negative market performance when they do occur) in the S&P 500^® Index, consisting of the two Underlying Index ETFs listed below which utilize futures contracts, swap agreements, and other financial investments to gain leveraged or inverse positions on the S&P 500 VIX Short-Term Futures Index (the “Short-Term VIX Futures” with such Underlying Index ETFs being the “Underlying Volatility ETFs”). The “VIX” refers to the Chicago Board Options Exchange, Incorporated Volatility Index. The VIX is designed to measure the market’s expectation of 30-day volatility in the S&P 500. The Short-Term VIX Futures measures the movements of a combination of VIX futures contracts and is designed to track changes in the expected volatility of the S&P 500 one month in the future. In other words, the volatility strategy seeks to hedge against “volatility” to the extent volatility is reflected in the prices of VIX futures.

The Underlying Index ETFs included in the Underlying Index and their investment exposure are set forth below:

Underlying Index ETFs


				Investment exposure
		Ticker	Underlying	(before fees and
Name	Investment Adviser	Symbol	Index	expenses)
Underlying Large Cap ETFs

SPDR S&P 500 ETF Trust	PDR Services, LLC, as Sponsor of the Trust (“Sponsor”), and State Street Bank and Trust Company, as Trustee of the Trust (“Trustee”)	SPY	S&P 500^® Index	Tracking of S&P 500^® Index

Vanguard S&P 500 ETF	The Vanguard Group, Inc.	VOO	S&P 500^® Index	Tracking of S&P 500^® Index

iShares Core S&P 500 ETF	BlackRock Fund Advisors	IVV	S&P 500^® Index	Tracking of S&P 500^® Index

Underlying Volatility ETFs

Ultra VIX Short-Term Futures ETF (the “Ultra Fund”)	ProShare Capital Management LLC	UVXY	S&P 500 VIX Short-Term Futures Index	Twice the return of Short-Term VIX Futures on a daily basis

Short VIX Short-Term Futures ETF (the “Short Fund”)	ProShare Capital Management LLC	SVXY	S&P 500 VIX Short-Term Futures Index	Inverse of the return of Short-Term VIX Futures on a daily basis

The Underlying Index allocates the Volatility Component to a target weight between the Underlying Volatility ETFs as follows:


Index	Target Allocation	Target Net Allocation
VelocityShares Volatility Hedged Large Cap Index	1/3 (Ultra Fund, with 2x exposure), 2/3 (Short Fund, with -1x exposure)	Neutral

3 ï Janus Velocity Volatility Hedged Large Cap ETF

The Volatility Component portion of the Underlying Index is rebalanced in a gradual manner over each quarter to preserve this allocation. This allocation results in a target net neutral exposure to the Short-Term VIX Futures, although market movement in VIX futures will result in allocations on any given day that differ, sometimes significantly from the target exposure, including the potential for net long or net short exposure. The Volatility Component is structured in a manner intended to benefit from sustained movements in either direction by Short-Term VIX Futures.

How the Fund Attempts to Replicate the Underlying Index

PRINCIPAL INVESTMENT RISKS

Investment Style Risk. Returns from large-capitalization stocks may trail returns from the overall stock market. Large-cap stocks may go through cycles of doing better or worse than other segments of the stock market or the stock market in general. These cycles may continue for extended periods of time. In addition, the Volatility Component may not be successful in hedging against market volatility at any time.

4 ï Janus Velocity Volatility Hedged Large Cap ETF

Swap Risk. The Fund expects to use cleared and over-the-counter (“OTC”) swap agreements in addition to other derivatives to obtain exposure to the Underlying Volatility ETFs and/or the VIX Short-Term Futures Index as a means to achieve its investment objective. An OTC swap contract is an agreement between two parties pursuant to which the parties exchange payments at specified dates on the basis of a specified notional amount, with the payments calculated by reference to specified securities, indices, reference rates, currencies or other instruments. Typically swap agreements provide that when the period payment dates for both parties are the same, the payments are made on a net basis (i.e., the two payment streams are netted out, with only the net amount paid by one party to the other). The Fund’s obligations or rights under a swap contract entered into on a net basis will generally be equal only to the net amount to be paid or received under the agreement, based on the relative values of the positions held by each party. Cleared swap transactions may help reduce counterparty credit risk. In a cleared swap, the Fund’s ultimate counterparty is a clearinghouse rather than a bank, dealer or financial institution. OTC swap agreements are not entered into or traded on exchanges and often there is no central clearing or guaranty function for swaps. These OTC swaps are often subject to credit risk or the risk of default or non-performance by the counterparty. Both OTC and cleared swaps could result in losses if interest rates or credit quality changes are not correctly anticipated by the Fund or if the reference index, security or investments do not perform as expected. The Dodd-Frank Wall Street Reform and Consumer Protection Act and related regulatory developments require the clearing and exchange-trading of certain standardized swap transactions. Mandatory exchange-trading and clearing is occurring on a phased-in basis.

Compounding Risk. Each of the Underlying Volatility ETFs has an investment objective to match (before fees and expenses) a multiple (i.e., 2x in the case of the Ultra Fund) or the inverse (i.e., -1x in the case of the Short Fund) of the performance of the Short-Term VIX Futures on a given day. Each Underlying Volatility ETF seeks investment results for a single day only, and not for any other period. The return of an Underlying Volatility ETF for a period longer than a day is the result of its return

5 ï Janus Velocity Volatility Hedged Large Cap ETF

for each day compounded over the period and usually will differ from twice (2x) or the inverse (-1x) of the return of the Fund’s index for the period. An Underlying Volatility ETF will lose money if the Short-Term VIX Futures performance is flat over time, and it is possible for an Underlying Volatility ETF to lose money over time even if the Short-Term VIX Futures’ performance increases (or decreases in the case of the Short Fund), as a result of daily rebalancing, the Short-Term VIX Futures’ volatility and compounding. Longer holding periods, higher index volatility and greater leverage each affect the impact of compounding on an Underlying Volatility ETF’s returns. Daily compounding of an Underlying Volatility ETF’s investment returns can dramatically and adversely affect its longer-term performance during periods of high volatility. Volatility may be at least as important to an Underlying Volatility ETF’s return for a period as the return of the Short-Term VIX Futures. The Underlying Volatility ETFs are not appropriate for direct investments for all investors and present different risks than most mutual funds.

However, the Fund’s exposures to the Underlying Volatility ETFs are part of a hedging strategy intended to reduce the risk of substantial declines in the S&P 500 due to a tail event or “increased volatility.” The Fund’s exposures to the Underlying Volatility ETFs (i) only represent up to 20% of the Fund’s portfolio, (ii) are comprised of offsetting holdings of leveraged and inverse positions on the Short-Term VIX Futures designed to minimize the effects of compounding in either a positive or negative direction, and (iii) are frequently rebalanced in a gradual manner to generally maintain a 15% allocation to the Volatility Component and the target net allocation of the Volatility Component’s overall exposure. Therefore, in the context of the Fund’s overall portfolio, the Fund’s investments in the Underlying Volatility ETFs present significantly different risks to an investor than a direct investment in an Underlying Volatility ETF.

Risk of Leveraged and Inverse Investment. The Ultra Fund utilizes leverage and the Short Fund utilizes inverse positions with respect to their respective indices. Accordingly, a substantial movement in the underlying index of an Underlying Volatility ETF in the opposite direction of the Underlying Volatility ETF’s position (e.g., a downward movement with respect to a leveraged position and an upward movement with respect to an inverse position) may result in a substantial loss of the Fund’s investment exposure to such Underlying Volatility ETF, up to the complete amount of the Fund’s investment. While the Fund’s exposures to Underlying Volatility ETFs are intended to balance each other out to an extent (as one Underlying Volatility ETF takes a leveraged position with respect to its underlying index while the other takes a short position), there is no guarantee that the Underlying Volatility ETFs’ offsetting positions will prevent the Fund from suffering losses. At any point in time, the Fund’s net exposure to volatility will vary, sometimes significantly from the target net allocation, and could result in a net short position due to daily decreases in VIX Futures prices. In such circumstances, the Fund could experience losses in its exposure to Underlying Volatility ETFs in the event of any increase in the underlying index of the Underlying Volatility ETF.

Liquidity Risk. Market illiquidity may cause losses for the Underlying Volatility ETFs. The large size of the positions which the Underlying Volatility ETFs may acquire increases the risk of illiquidity by both making their positions more difficult to liquidate and increasing the losses incurred while trying to do so. Any type of disruption or illiquidity will potentially be exacerbated due to the fact that the Underlying Volatility ETFs will typically invest in financial instruments related to one benchmark (the Short-Term VIX Futures), which in many cases is highly concentrated.

Fluctuation of Net Asset Value. The NAV of the shares of an Underlying Index ETF will generally fluctuate with changes in the market value of the Underlying Index ETF’s portfolio. The market prices of the Underlying Index ETF shares will generally fluctuate in accordance with changes in NAV as well as the relative supply of, and demand for, the Underlying Index ETF shares on the applicable listing exchange. The Underlying Index ETF shares may thus trade below, at or above their NAV. If the Fund purchases shares at a time when the market price is at a premium to the NAV of the shares or sells at a time when the market price is at a discount to the NAV of the shares, then the Fund may sustain losses. Price differences may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for the

6 ï Janus Velocity Volatility Hedged Large Cap ETF

Underlying Index ETF shares will be closely related to, but not identical to, the same forces influencing the prices of stocks and/or financial instruments individually or in the aggregate at any point in time by an Underlying Index ETF.

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

MANAGEMENT

Investment Adviser: Janus Capital Management LLC

PURCHASE AND SALE OF FUND SHARES

Unlike shares of traditional mutual funds, shares of the Fund are not individually redeemable and may only be purchased or redeemed directly from the Fund at net asset value (“NAV”) in large increments called “Creation Units” (50,000 or more shares per Creation Unit) through certain participants, known as “Authorized Participants.” The Fund will issue or redeem Creation Units in exchange for portfolio securities included in the Fund’s Underlying Index and/or cash. Because the Fund uses swap instruments, which require cash to establish, maintain and settle transactions, and cannot be readily transferred, the Fund will need to issue and redeem Creation Units partially for cash under normal circumstances. Except when aggregated in Creation Units, Fund shares are not redeemable securities of the Fund.

TAX INFORMATION

7 ï Janus Velocity Volatility Hedged Large Cap ETF

Additional information about the Fund

FEES AND EXPENSES


•	“Annual Fund Operating Expenses” are paid out of the Fund’s assets. You do not pay these fees directly but, as the Example in the Fund Summary shows, these costs are borne indirectly by all shareholders.

•	The “Management Fee” is the rate paid by the Fund to Janus Capital for providing certain services. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•	“Other Expenses” include taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, securities lending expenses, and extraordinary expenses (such as litigation and indemnification expenses).


•	All expenses in the Fund’s “Fees and Expenses of the Fund” table are shown without the effect of expense offset arrangements. Pursuant to such arrangements, credits realized as a result of uninvested cash balances are used to reduce custodian and transfer agent expenses.

ADDITIONAL INVESTMENT STRATEGIES AND GENERAL PORTFOLIO POLICIES

The Fund may borrow money from a bank up to a limit of 10% of the value of its assets, but only for temporary or emergency purposes.

Nondiversification

9 ï Janus Detroit Street Trust

Securities Lending

RISKS OF THE FUND

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These risks are described further in the Statement of Additional Information.

INFORMATION REGARDING THE UNDERLYING INDEX

The Underlying Index and its Allocations

The VelocityShares Volatility Hedged Large Cap Index reflects the performance of a portfolio consisting of an exposure to (1) a large cap equity portfolio, consisting of the three Underlying Index ETFs listed below which track the Standard & Poor’s 500^® Index (the “S&P 500^® Index,” with the Underlying Index ETFs tracking the S&P 500^® Index being the “Underlying Large Cap ETFs”) and (2) a volatility strategy to hedge moderate volatility, consisting of the two Underlying Index ETFs listed below which utilize futures contracts, swap agreements and other financial investments to gain leveraged or inverse positions on the S&P 500 VIX (Chicago Board Options Exchange, Incorporated Volatility Index (the “VIX”)) Short-Term Futures Index (the “Short-Term VIX Futures;” with such Underlying Index ETFs being the “Underlying Volatility ETFs”).

The Underlying Index consists of an 85% allocation to the Underlying Large Cap ETFs (split evenly between each Underlying Large Cap ETF) and a 15% allocation to the Underlying Volatility ETFs (the “Volatility Component”). The Volatility Component in the Underlying Index seeks to replicate long/short exposure to short-dated VIX futures, but with a targeted neutral exposure as set forth in the table below under “Index Description.”

How the Fund Attempts to Replicate its Underlying Index

The Fund will attempt to correspond generally, before fees and expenses, to the performance of the Underlying Index by investing under normal circumstances in (a) shares of the Underlying Large Cap ETFs and (b) one or more derivative instruments (primarily swaps), designed to replicate the performance of the volatility component directly by reference to closing prices of the underlying VIX futures. The Fund could also elect to trade VIX futures directly, although the Fund does not expect to use such instruments under normal circumstances. The Fund may also invest directly in shares of the Underlying Volatility ETFs, though the Fund does not currently intend to do so. While the Underlying Volatility ETFs utilize futures contracts, swap agreements and other financial instruments, the Fund’s only direct use of such instruments will be solely as described in (b) above.

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Volatility Strategy Target Allocation


Index	Target Allocation	Target Net Allocation
VelocityShares Volatility Hedged Large Cap Index	1/3 (Ultra Fund, with 2x exposure), 2/3 (Short Fund, with -1x exposure)	Neutral

On a weekly basis, the exposures of one of the 13 sub-portfolios is rebalanced to its target allocation, such that during a quarter each of the sub-portfolios is rebalanced.

The Underlying Index ETFs which currently constitute the Underlying Index are set forth in the table below:

Underlying Index ETFs


				Investment exposure
		Ticker	Underlying	(before fees and
Name	Investment Adviser	Symbol	Index	expenses)
Underlying Large Cap ETFs

SPDR S&P 500 ETF Trust	PDR Services, LLC, as Sponsor of the Trust (“Sponsor”), and State Street Bank and Trust Company, as Trustee of the Trust (“Trustee”)	SPY	S&P 500 Index	Tracking of S&P 500 Index

Vanguard S&P 500 ETF	The Vanguard Group, Inc.	VOO	S&P 500 Index	Tracking of S&P 500 Index

iShares Core S&P 500 ETF	BlackRock Fund Advisors	IVV	S&P 500 Index	Tracking of S&P 500 Index

Underlying Volatility ETFs

Ultra VIX Short-Term Futures ETF (the “Ultra Fund”)	ProShare Capital Management LLC	UVXY	S&P 500 VIX Short-Term Futures Index	Twice the return of Short-Term VIX Futures on a daily basis

Short VIX Short-Term Futures ETF (the “Short Fund”)	ProShare Capital Management LLC	SVXY	S&P 500 VIX Short-Term Futures Index	Inverse of the return of Short-Term VIX Futures on a daily basis

12 ï Janus Detroit Street Trust

Management of the Fund

INVESTMENT ADVISER

The Trustees and the initial shareholder of the Fund have approved the use of a manager-of-managers structure for the Fund.

MANAGEMENT EXPENSES

The Fund’s investment advisory fee is calculated daily and paid monthly. The Fund’s advisory agreement details the investment advisory fee and other expenses that the Fund must pay.

The following table reflects the Fund’s contractual Management Fee rate (expressed as an annual rate). The rate shown is a fixed rate based on the Fund’s average daily net assets.


	Average Daily		Contractual
	Net Assets		Management Fee (%)
Fund Name	of the Fund		(annual rate)
Janus Velocity Volatility Hedged Large Cap ETF		All Asset Levels		0.65

13 ï Janus Detroit Street Trust

INVESTMENT PERSONNEL

Janus Velocity Volatility Hedged Large Cap ETF

Information about the portfolio managers’ compensation structure and other accounts managed is included in the SAI.

Conflicts of Interest

14 ï Janus Detroit Street Trust

Other information

DISTRIBUTION OF THE FUND

INDEX PROVIDER

Janus Index & Calculation Services LLC (“Janus Index Services”) is the Index Provider for the Underlying Index. Janus Capital has entered into a license agreement with Janus Index Services to use the Underlying Index. Janus Index Services is affiliated with the Fund and Janus Capital. This affiliation may create potential conflicts for Janus Index Services as it may have an interest in the performance of the Fund, which could motivate it to alter the index methodology for the Underlying Index. Janus Index Services has adopted procedures that it believes are reasonably designed to mitigate these and other potential conflicts.

Disclaimers

Janus Index Services is the licensor of certain trademarks, service marks, and trade names.

Neither Janus Index Services nor any of its affiliates make any representation or warranty, express or implied, to the owners of the Fund or any member of the public regarding the advisability of investing in securities generally or in the Fund particularly or the ability of the Underlying Index to track general market performance. The Underlying Index is determined, composed, and calculated by Janus Index Services without regard to Janus Capital or the Fund. Janus Index Services has no obligation to take the needs of Janus Capital or the owners of the Fund into consideration in determining, composing, or calculating the Index. Janus Index Services is not responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Fund to be issued or in the determination or calculation of the equation by which the Fund is to be converted into cash.

15 ï Janus Detroit Street Trust

Dividends, distributions, and taxes

DISTRIBUTIONS

Distribution Schedule

How Distributions Affect the Fund’s NAV

TAXES

Taxes on Distributions

16 ï Janus Detroit Street Trust

Taxes on Sales

Taxation of the Fund

Dividends, interest, and some capital gains received by the Fund on foreign securities may be subject to foreign tax withholding or other foreign taxes.

17 ï Janus Detroit Street Trust

Shareholder’s guide

The Fund issues or redeems its shares at NAV per share only in Creation Units. Shares of the Fund are listed for trading on a national securities exchange and trade on the secondary market during the trading day. Shares can be bought and sold throughout the trading day like shares of other publicly traded companies. There is no minimum investment. When buying or selling Fund shares through a broker, you will incur customary brokerage commissions and charges, and you may pay some or all of the spread between the bid and offered price in the secondary market on each purchase and sale transaction. Fund shares are traded on NYSE Arca under the trading symbol SPXH. Share prices are reported in dollars and cents per share.

PRICING OF FUND SHARES

All purchases, sales, or other account activity must be processed through your financial intermediary or plan sponsor.

DISTRIBUTION AND SERVICING FEES

Distribution and Shareholder Servicing Plan

18 ï Janus Detroit Street Trust

PAYMENTS TO FINANCIAL INTERMEDIARIES BY JANUS CAPITAL OR ITS AFFILIATES

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preferred or recommended funds and/or the provision of preferential or enhanced opportunities to promote the Janus funds in various ways within such financial intermediary’s organization.

PURCHASING AND SELLING SHARES

Continuous Offering

20 ï Janus Detroit Street Trust

Book Entry

Share Prices

Premiums and Discounts

21 ï Janus Detroit Street Trust

Investments by Other Investment Companies

The Trust and the Fund are part of the Janus family of funds and are related for purposes of investor and investment services, as defined in Section 12(d)(1)(G) of the 1940 Act.

EXCESSIVE TRADING

AVAILABILITY OF PORTFOLIO HOLDINGS INFORMATION

Each business day, the Fund’s portfolio holdings information is provided to the Distributor or other agent for dissemination through the facilities of the NSCC and/or other fee-based subscription services to NSCC members and/or subscribers to entities that publish and/or analyze such information in connection with the process of purchasing or redeeming Creation Units or trading shares of the Fund in the secondary market. In addition, on each business day before commencement of trading in shares on the NYSE Arca, the Fund will disclose on janus.com/etfs the identities and quantities of each portfolio position held by the Fund that will form the basis for the Fund’s calculation of the NAV per share at the end of the business day. The Fund is also required to disclose its complete holdings in the quarterly holdings report on Form N-Q within 60 days of the end of the first and third fiscal quarters, and in the annual report and semiannual report to Fund shareholders.

For additional information on these disclosures and the availability of portfolio holdings information, please refer to the Fund’s SAI.

SHAREHOLDER COMMUNICATIONS

Statements and Reports

Your financial intermediary or plan sponsor is responsible for sending you periodic statements of all transactions, along with trade confirmations and tax reporting, as required by applicable law.

22 ï Janus Detroit Street Trust

Lost (Unclaimed/Abandoned) Accounts

23 ï Janus Detroit Street Trust

janus.com/etfs

151 Detroit Street

Denver, CO 80206-4805

1-877-335-2687

The Trust’s Investment Company Act File No. is 811-23112.

The information in this Statement of Additional Information is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This Statement of Additional Information is not an offer to sell these securities and is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

6 [ , 2016]

Subject to Completion

Preliminary Statement of Additional Information Dated February 18, 2016


	Ticker	Stock Exchange
Janus Small Cap Growth Alpha ETF	JSML	NASDAQ Stock Market, Inc.
Janus Small/Mid Cap Growth Alpha ETF	JSMD	NASDAQ Stock Market, Inc.

Janus Detroit Street Trust

Statement of Additional Information

This Statement of Additional Information (“SAI”) expands upon and supplements the information contained in the current Prospectuses of Janus Small Cap Growth Alpha ETF and Janus Small/Mid Cap Growth Alpha ETF (each, a “Fund” and collectively, the “Funds”), each of which is a separate series of Janus Detroit Street Trust, a Delaware statutory trust (the “Trust”). Each of these series of the Trust represents shares of beneficial interest in a separate portfolio of securities and other assets with its own objective and policies.

This SAI is not a Prospectus and should be read in conjunction with the Funds’ Prospectuses dated [ , 2016], and any supplements thereto, which are incorporated by reference into this SAI and may be obtained by contacting your broker-dealer, plan sponsor, or financial intermediary, at janus.com/etfs, or by contacting a Janus representative at 1-877-335-2687. This SAI contains additional and more detailed information about the Funds’ operations and activities than the Prospectuses. The Annual and Semiannual Reports (as they become available) are available, without charge, by contacting your broker-dealer, plan sponsor, or financial intermediary, at janus.com/etfs, or by contacting a Janus representative at 1-877-335-2687.

Classification, investment policies and restrictions,
and investment strategies and risks

JANUS DETROIT STREET TRUST

This Statement of Additional Information includes information about Janus Small Cap Growth Alpha ETF and Janus Small/Mid Cap Growth Alpha ETF (each, a “Fund” and, collectively, the “Funds”), each of which operates as an exchange-traded fund (“ETF”) and is a series of the Trust, an open-end, management investment company.

Each Fund offers and issues shares at its net asset value per share (“NAV”) only in aggregations of a specified number of shares (“Creation Unit”), generally in exchange for a designated portfolio of securities (including any portion of such securities for which cash may be substituted) (the “Deposit Securities”), together with the deposit of a specified cash payment (the “Cash Component”), or in certain circumstances, for an all cash payment. Shares of each Fund are listed for trading on NASDAQ Stock Market, Inc. (“NASDAQ” or the “Listing Exchange”), a national securities exchange. Shares of each Fund are traded in the secondary market and elsewhere at market prices that may be at, above or below the Fund’s NAV. Unlike mutual funds, each Fund’s shares are not individually redeemable securities. Rather, each Fund’s shares are redeemable only in Creation Units, and, generally, in exchange for portfolio securities and a Cash Component. Creation Units typically are a specified number of shares, generally 50,000 or multiples thereof. In the event of liquidation of a Fund, the Trust may lower the number of shares in a Creation Unit.

The Trust may issue and redeem shares in-kind and/or for cash. A Fund may charge creation/redemption transaction fees for each creation and redemption. In all cases, transaction fees will be limited in accordance with the requirements of the SEC applicable to management investment companies offering redeemable securities. Some of the information in this SAI and the Prospectus, such as information about purchasing and redeeming shares from a Fund and transaction fees, is not relevant to most retail investors because it applies only to transactions for Creation Units. Refer to “Creation and Redemption of Creation Units”.

Once created, a Fund’s shares generally trade in the secondary market, at market prices that change throughout the day, in amounts less than a Creation Unit. Investors purchasing a Fund’s shares in the secondary market through a brokerage account or with the assistance of a broker may be subject to brokerage commissions and charges.

EXCHANGE LISTING AND TRADING

Shares of each Fund are listed for trading and trade throughout the day on the Listing Exchange and other secondary markets. There can be no assurance that the requirements of the Listing Exchange necessary to maintain the listing of shares of each Fund will continue to be met. The Listing Exchange may, but is not required to, remove the shares of a Fund from listing if: (i) following the initial 12-month period beginning upon the commencement of trading of Fund shares, there are fewer than 50 beneficial owners of shares of a Fund for 30 or more consecutive trading days; (ii) the value of Janus Small Cap Growth Alpha ETF’s underlying index (“Janus Small Cap Growth Alpha Index”) and Janus Small/Mid Cap Growth Alpha ETF’s underlying index (“Janus Small/Mid Cap Growth Alpha Index”) (each, an “Underlying Index”) is no longer calculated or available; or (iii) any other event shall occur or condition shall exist that, in the opinion of the Listing Exchange, makes further dealings on the Listing Exchange inadvisable. The Listing Exchange will remove the shares of a Fund from listing and trading upon termination of a Fund. In the event a Fund ceases to be listed on an exchange, a Fund may cease operating as an “exchange-traded” fund and operate as a mutual fund, provided that shareholders are given advance notice.

As in the case of other publicly-traded securities, when you buy or sell shares through a financial intermediary you will incur a brokerage commission determined by that financial intermediary.

In order to provide additional information regarding the intra-day value of shares of a Fund, the Listing Exchange or a market data vendor disseminates every 15 seconds through the facilities of the Consolidated Tape Association or other widely disseminated means an updated intra-day net asset value (“iNAV”) for each Fund as calculated by an information provider or market data vendor. The Trust is not involved in or responsible for any aspect of the calculation or dissemination of the iNAV and makes no representation or warranty as to the accuracy of the iNAV.

Shares of each Fund trade on the Listing Exchange or in the secondary market at prices that may differ from their NAV or iNAV, because such prices may be affected by market forces (such as supply and demand for a Fund’s shares). The Trust reserves the right to adjust the share prices of each Fund in the future to maintain convenient trading ranges for investors. Any adjustments would be accomplished through stock splits or reverse stock splits, which would have no effect on the net assets of a Fund.

Each Fund is not sponsored, endorsed, sold, or promoted by the Listing Exchange. The Listing Exchange makes no representation or warranty, express or implied, to the owners of shares of a Fund or any member of the public regarding the advisability of investing in securities generally or in a Fund particularly or the ability of a Fund to achieve its objectives.

CLASSIFICATION

The Investment Company Act of 1940, as amended (“1940 Act”), classifies funds as either diversified or nondiversified. Each Fund is classified as diversified.

ADVISER

Janus Capital Management LLC (“Janus Capital” or “Janus”) is the investment adviser for each Fund.

INVESTMENT POLICIES AND RESTRICTIONS

Each Fund is subject to certain fundamental policies and restrictions that may not be changed without shareholder approval. Shareholder approval means approval by the lesser of: (i) more than 50% of the outstanding voting securities of the Trust (or a particular Fund if a matter affects just that Fund) or (ii) 67% or more of the voting securities present at a meeting if the holders of more than 50% of the outstanding voting securities of the Trust (or a particular Fund) are present or represented by proxy. The following policies are fundamental policies of the Funds.

(1) With respect to 75% of its total assets, each Fund may not purchase securities of an issuer (other than the U.S. Government, its agencies, instrumentalities or authorities, or repurchase agreements collateralized by U.S. Government securities, and securities of other investment companies) if: (a) such purchase would, at the time, cause more than 5% of the Fund’s total assets taken at market value to be invested in the securities of such issuer or (b) such purchase would, at the time, result in more than 10% of the outstanding voting securities of such issuer being held by the Fund.

Each Fund may not:

(2) Invest 25% or more of the value of its total assets in any particular industry or group of industries (other than U.S. Government securities and securities of other investment companies), except to the extent each Fund’s Underlying Index concentrates in the securities of a particular industry or group of industries, the Fund will concentrate its investments to approximately the same extent as its Underlying Index.

(3) Purchase or sell physical commodities unless acquired as a result of ownership of securities or other instruments (but this limitation shall not prevent a Fund from purchasing or selling foreign currencies, options, futures, swaps, forward contracts, or other derivative instruments, or from investing in securities or other instruments backed by physical commodities).

(4) Lend any security or make any other loan if, as a result, more than one-third of a Fund’s total assets would be lent to other parties (but this limitation does not apply to investments in repurchase agreements, commercial paper, debt securities, or loans, including assignments and participation interests).

(5) Act as an underwriter of securities issued by others, except to the extent that a Fund may be deemed an underwriter in connection with the disposition of its portfolio securities.

(6) Borrow money except that a Fund may borrow money for temporary or emergency purposes (not for leveraging or investment). Borrowings from banks will not, in any event, exceed one-third of the value of a Fund’s total assets (including the amount borrowed). This policy shall not prohibit short sales transactions, or futures, options, swaps, repurchase transactions (including reverse repurchase agreements), or forward transactions. A Fund may not issue “senior securities” in contravention of the 1940 Act.

(7) Invest directly in real estate or interests in real estate; however, a Fund may own debt or equity securities issued by companies engaged in those businesses.

As a fundamental policy, a Fund may, notwithstanding any other investment policy or limitation (whether or not fundamental), invest all of its assets in the securities of a single open-end management investment company with substantially the same fundamental investment objectives, policies, and limitations as the Fund.

The Board of Trustees (“Trustees”) has adopted additional investment restrictions for the Funds. These restrictions are operating policies of the Funds and may be changed by the Trustees without shareholder approval. The additional restrictions adopted by the Trustees to date include the following:

(1) If a Fund is an underlying fund in a fund of funds, the Fund may not acquire securities of other investment companies in reliance on Section 12(d)(1)(F) of the 1940 Act and securities of open-end investment companies or registered unit investment trusts in reliance on Section 12(d)(1)(G) of the 1940 Act.

(2) A Fund may sell securities short if it owns or has the right to obtain securities equivalent in kind and amount to the securities sold short without the payment of any additional consideration therefor (“short sales against the box”). In addition, a Fund may engage in short sales other than against the box, which involve selling a security that the Fund borrows and does not own. The Trustees may impose limits on a Fund’s investments in short sales, as described in the Fund’s Prospectus. Transactions in futures, options, swaps, and forward contracts not involving short sales are not deemed to constitute selling securities short.

(3) The Funds do not intend to purchase securities on margin, except that the Funds may obtain such short-term credits as are necessary for the clearance of transactions, and provided that margin payments and other deposits in connection with transactions involving short sales, futures, options, swaps, forward contracts, and other permitted investment techniques shall not be deemed to constitute purchasing securities on margin.

(4) A Fund may not mortgage or pledge any securities owned or held by the Fund in amounts that exceed, in the aggregate, 15% of the Fund’s net asset value (“NAV”), provided that this limitation does not apply to: reverse repurchase agreements; deposits of assets to margin; guarantee positions in futures, options, swaps, or forward contracts; or the segregation of assets in connection with such contracts.

(5) The Funds do not currently intend to purchase any security or enter into a repurchase agreement if, as a result, more than 15% of its net assets would be invested in repurchase agreements not entitling the holder to payment of principal and interest within seven days and in securities that are illiquid by virtue of legal or contractual restrictions on resale or the absence of a readily available market. The Trustees, or the Funds’ investment adviser acting pursuant to authority delegated by the Trustees, may determine that a readily available market exists for: securities eligible for resale pursuant to Rule 144A under the Securities Act of 1933, as amended (“Rule 144A Securities”), or any successor to such rule; Section 4(2) commercial paper; and municipal lease obligations. Accordingly, such securities may not be subject to the foregoing limitation. Certain securities previously deemed liquid may become illiquid in any subsequent assessment of liquidity factors affecting the security.

(6) The Funds may not invest in companies for the purpose of exercising control of management.

Under the terms of an exemptive order received from the Securities and Exchange Commission (“SEC”), a Fund may borrow money from or lend money to other funds that permit such transactions and for which Janus Capital or one of its affiliates serves as investment adviser. All such borrowing and lending will be subject to the above limits and to the limits and other conditions in such exemptive order. Each Fund will borrow money through the program only when the costs are equal to or lower than the cost of bank loans. Interfund loans and borrowings normally extend overnight, but can have a maximum duration of seven days. Each Fund will lend through the program only when the returns are higher than those available from other short-term instruments (such as repurchase agreements). A Fund may have to borrow from a bank at a higher interest rate if an interfund loan is called or not renewed. Any delay in repayment to a lending Fund could result in a lost investment opportunity or additional borrowing costs, and interfund loans are subject to the risk that the borrowing Fund may be unable to repay the loan when due. While it is expected that a Fund may borrow money through the program to satisfy redemption requests or to cover unanticipated cash shortfalls, a Fund may elect to not participate in the program during times of market uncertainty or distress or for other reasons.

For purposes of these investment restrictions, the identification of the issuer of a municipal obligation depends on the terms and conditions of the security. When assets and revenues of a political subdivision are separate from those of the government that created the subdivision and the security is backed only by the assets and revenues of the subdivision, the subdivision is deemed to be the sole issuer. Similarly, in the case of an industrial development bond, if the bond is backed only by assets and revenues of a nongovernmental user, then the nongovernmental user would be deemed to be the sole issuer. If, however, in either case, the creating government or some other entity guarantees the security, the guarantee would be considered a separate security that would be treated as an issue of the guaranteeing entity.

For purposes of the Funds’ fundamental policy related to investments in real estate, the policy does not prohibit the purchase of securities directly or indirectly secured by real estate or interests therein, or issued by entities that invest in real estate or

interests therein, such as, but not limited to, corporations, partnerships, real estate investment trusts (“REITs”), and other REIT-like entities, such as foreign entities that have REIT characteristics.

Except for the Funds’ policies with respect to investments in illiquid securities and borrowing, the percentage limitations included in these policies and elsewhere in this SAI and/or the Funds’ Prospectuses normally apply only at the time of purchase of a security. So, for example, if a Fund exceeds a limit as a result of market fluctuations or the sale of other securities, it will not be required to dispose of any securities.

For purposes of each Fund’s policies on investing in particular industries, each Fund relies primarily on industry or industry group classifications under the Global Industry Classification Standard (“GICS”) developed by MSCI. To the extent that the above classifications are so broad that the primary economic characteristics in a single class are materially different, a Fund may further classify issuers in accordance with industry classifications consistent with relevant SEC staff interpretations. The Funds may change any source used for determining industry classifications without prior shareholder notice or approval.

INVESTMENT STRATEGIES AND RISKS

Each Fund seeks investment results that correspond generally, before fees and expenses, to the performance of its respective Underlying Index. A discussion of the risks associated with an investment in each Fund is contained in each Fund’s Prospectus under the headings “Principal Investment Risks” and “Risks of the Fund.” The discussion below supplements, and should be read in conjunction with, such sections of each Fund’s Prospectus.

General Considerations and Risks

Investment in a Fund should be made with an understanding that the value of the portfolio of securities held by the Fund may fluctuate in accordance with changes in the financial condition of the issuers of the portfolio securities, the value of common stocks generally and other factors.

Each Fund is not actively managed by traditional methods and therefore the adverse financial condition of any one issuer will not result in the elimination of its securities from the portfolio securities held by the Fund unless the securities of such issuer are removed from the Underlying Index.

An investment in a Fund should also be made with an understanding that a Fund will not be able to replicate exactly the performance of the Underlying Index because the total return generated by its portfolio securities will be reduced by transaction costs incurred in adjusting the actual balance of such securities and other Fund expenses, whereas such transaction costs and expenses are not included in the calculation of the Underlying Index. It is also possible that for short periods of time, a Fund may not fully replicate the performance of the Underlying Index due to the temporary unavailability of certain Underlying Index securities in the secondary market or due to other extraordinary circumstances. Such events are unlikely to continue for an extended period of time because a Fund is required to correct such imbalances by means of adjusting the composition of its portfolio securities.

An investment in a Fund should also be made with an understanding of the risks inherent in an investment in securities, including the risk that the financial condition of issuers may become impaired or that the general condition of the securities markets may deteriorate (either of which may cause a decrease in the value of the portfolio securities and thus in the value of shares). Securities are susceptible to general market fluctuations and to volatile increases and decreases in value as market confidence in and perceptions of their issuers change. These investor perceptions are based on various and unpredictable factors including expectations regarding government, economic, monetary and fiscal policies, inflation and interest rates, economic expansion or contraction, and global or regional political, economic and banking crises.

Holders of common stocks incur more risk than holders of preferred stocks and debt obligations because common stockholders, as owners of the issuer, have generally inferior rights to receive payments from the issuer in comparison with the rights of creditors of, or holders of debt obligations or preferred stocks issued by, the issuer. Further, unlike debt securities which typically have a stated principal amount payable at maturity (whose value, however, will be subject to market fluctuations prior thereto), or preferred stocks which typically have a liquidation preference and which may have stated optional or mandatory redemption provisions, common stocks have neither a fixed principal amount nor a maturity. Common stock values are subject to market fluctuations as long as the common stock remains outstanding.

The principal trading market for some of the securities in an index may be in the over-the-counter market. The existence of a liquid trading market for certain securities may depend on whether dealers will make a market in such securities. There can be no assurance that a market will be made or maintained or that any such market will be or remain liquid. The price at

which securities may be sold and the value of a Fund’s shares will be adversely affected if trading markets for a Fund’s portfolio securities are limited or absent or if bid/ask spreads are wide.

Cybersecurity

With the increased use of the Internet to conduct business, the Funds are susceptible to operational and information security risks. In general cyber incidents can result from deliberate attacks or unintentional events. Cyber-attacks include, but are not limited to, infection by computer viruses or other malicious software code, gaining unauthorized access to systems, networks, or devices that are used to service the Funds’ operations through “hacking” or other means for the purpose of misappropriating assets or sensitive information, corrupting data, or causing operational disruption. Cyber-attacks may also be carried out in a manner that does not require gaining unauthorized access, such as causing denial-of-service attacks on the Funds’ website. In addition, authorized persons could inadvertently or intentionally release confidential or proprietary information stored on the Funds’ systems.

Cyber security failures or breaches by the Funds’ third party service providers (including, but not limited to, Janus Capital, custodians, transfer agents, and financial intermediaries), or the subadvisers (if applicable) may cause disruptions and impact the service providers’ and the Funds’ business operations, potentially resulting in financial losses, the inability of fund shareholders to transact business and the Funds to process transactions, inability to calculate a Fund’s net asset value, violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement or other compensation costs, and/or additional compliance costs. The Funds may incur incremental costs to prevent cyber incidents in the future. The Funds and their shareholders could be negatively impacted as a result. While Janus Capital has established business continuity plans and risk management systems designed to prevent or reduce the impact of such cyber-attacks, there are inherent limitations in such plans and systems due in part to the ever-changing nature of technology and cyber-attack tactics. As such, there is a possibility that certain risks have not been adequately identified or prepared for. Furthermore, the Funds cannot directly control any cyber security plans and systems put in place by third party service providers. Cyber security risks are also present for issuers of securities in which a Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund’s investment in such securities to lose value.

Equity Securities

The Funds may invest in equity securities, which include, but are not limited to, common and preferred stocks and securities convertible or exchangeable into common stock.

Common Stock. Common stock represents a proportionate share of the ownership of a company. Common stocks sometimes are divided into several classes, with each class having different voting rights, dividend rights, or other differences in their rights and priorities. The value of a stock is based on the market’s assessment of the current and future success of a company’s business, any income paid to stockholders, the value of the company’s assets, and general market conditions. The value of a stock may also be adversely affected by other factors such as accounting irregularities, actual or perceived weaknesses in corporate governance practices of a company’s board or management, and changes in company management. Common stock values can fluctuate dramatically over short periods.

Preferred Stock. A preferred stock represents an ownership interest in a company, but pays dividends at a specific rate and has priority over common stock in payment of dividends and liquidation claims. Preferred stock dividends are generally cumulative, noncumulative, or participating. “Cumulative” dividend provisions require all or a portion of prior unpaid dividends to be paid before dividends can be paid to the issuer’s common stock. “Participating” preferred stock may be entitled to a dividend exceeding the stated dividend in certain cases. Like debt securities, the value of a preferred stock often fluctuates more in response to changes in interest rates and the creditworthiness of the issuer, rather than in response to changes in the issuer’s profitability and business prospects. Preferred stock is subject to similar risks as common stock and debt securities.

Convertible Security. A convertible security is generally a debt obligation or preferred stock that may be converted within a specified period of time into a certain amount of common stock of the same or a different issuer. A convertible security, such as a “convertible preferred stock,” provides a fixed-income stream and the opportunity, through its conversion feature, to participate in the capital appreciation resulting from a market price advance in its underlying common stock. Like a common stock, the value of a convertible security tends to increase as the market value of the underlying stock rises, and it tends to decrease as the market value of the underlying stock declines. As with a fixed-income security, a convertible security tends to increase in market value when interest rates decline and decrease in value when interest rates rise. Because both interest rate and market movements can influence its value, a convertible security is not as sensitive to interest rates as a similar fixed-income security, nor is it as sensitive to changes in share price as its underlying stock.

Convertible securities generally have less potential for gain or loss than common stocks. Convertible securities generally provide yields higher than the underlying common stocks, but generally lower than comparable non-convertible securities. Because of this higher yield, convertible securities generally sell at prices above their “conversion value,” which is the current market value of the stock to be received upon conversion. The difference between this conversion value and the price of convertible securities will vary over time depending on changes in the value of the underlying common stocks and interest rates.

A convertible security may also be called for redemption or conversion by the issuer after a particular date and under certain circumstances (including a specified price) established upon issue. If a convertible security held by a Fund is called for redemption or conversion, the Fund could be required to tender it for redemption, convert it into the underlying common stock, or sell it to a third party.

Foreign Securities

Each Fund may invest in foreign securities either indirectly (e.g., depositary receipts, depositary shares, and passive foreign investment companies) or directly in foreign markets, including emerging markets. Investments in foreign securities may include, but are not necessarily limited to, corporate debt securities of foreign issuers, preferred or preference stock of foreign issuers, certain foreign bank obligations, and U.S. dollar or foreign currency-denominated obligations of foreign governments or supranational entities or their subdivisions, agencies, and instrumentalities. Investments in foreign securities, including securities of foreign and emerging market governments, may involve greater risks than investing in domestic securities because a Fund’s performance may depend on factors other than the performance of a particular company. These factors include:

Currency Risk. As long as a Fund holds a foreign security, its value will be affected by the value of the local currency relative to the U.S. dollar. When a 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.

Political and Economic Risk. Foreign investments may be subject to heightened political and economic risks, particularly in emerging markets which may have relatively unstable governments, immature economic structures, national policies restricting investments by foreigners, social instability, and different and/or developing legal systems. In some countries, there is the risk that the government may take over the assets or operations of a company or that the government may impose withholding and other taxes or limits on the removal of a Fund’s assets from that country. In addition, the economies of emerging markets may be predominantly based on only a few industries, may be highly vulnerable to changes in local or global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates.

Regulatory Risk. There may be less government supervision of foreign markets. As a result, foreign issuers may not be subject to the uniform accounting, auditing, and financial reporting standards and practices applicable to domestic issuers, and there may be less publicly available information about foreign issuers.

Foreign Market Risk. Foreign securities markets, particularly those of emerging market countries, may be less liquid and more volatile than domestic markets. These securities markets may trade a small number of securities, may have a limited number of issuers and a high proportion of shares, or may be held by a relatively small number of persons or institutions. Local securities markets may be unable to respond effectively to increases in trading volume, potentially making prompt liquidation of substantial holdings difficult or impossible at times. It is also possible that certain markets may require payment for securities before delivery, and delays may be encountered in settling securities transactions. In some foreign markets, there may not be protection against failure by other parties to complete transactions. It may not be possible for a Fund to repatriate capital, dividends, interest, and other income from a particular country or governmental entity. In addition, securities of issuers located in or economically tied to countries with emerging markets may have limited marketability and may be subject to more abrupt or erratic price movements which could also have a negative effect on a Fund. Such factors may hinder a Fund’s ability to buy and sell emerging market securities in a timely manner, affecting the Fund’s investment strategies and potentially affecting the value of the Fund.

Geographic Investment Risk. To the extent a Fund invests a significant portion of its assets in a particular country or geographic region, the Fund will generally have more exposure to certain risks due to possible political, economic, social, or regulatory events in that country or region. 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 a Fund’s performance.

Transaction Costs. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

Loans of Portfolio Securities

Each Fund may lend its investment securities to approved borrowers. Any gain or loss on the market price of the securities loaned that might occur during the term of the loan would be for the account of a Fund. These loans cannot exceed one-third of a Fund’s total assets.

Approved borrowers are brokers, dealers, domestic and foreign banks, or other financial institutions that meet credit or other requirements as established by, and subject to the review of, the Trust’s Board, so long as the terms, the structure and the aggregate amount of such loans are not inconsistent with the 1940 Act and the rules and regulations thereunder or interpretations of the SEC, which require that (a) the borrowers pledge and maintain with the applicable Fund collateral consisting of cash, an irrevocable letter of credit issued by a bank, or securities issued or guaranteed by the U.S. Government having a value at all times of not less than 102% of the value of the securities loaned (on a “mark-to-market” basis); (b) the loan be made subject to termination by a Fund at any time; and (c) a Fund receives reasonable interest on the loan. From time to time, a Fund may return a part of the interest earned from the investment of collateral received from securities loaned to the borrower and/or a third party that is unaffiliated with a Fund and that is acting as a finder.

Illiquid Securities

Each Fund may invest up to an aggregate amount of 15% of its net assets in illiquid securities. Illiquid securities are securities that cannot be sold or disposed of within seven days at their approximate current value, and include securities subject to contractual or other restrictions on resale and other instruments that lack readily available markets.

Money Market Instruments

Each Fund may invest a portion of their assets in high-quality money market instruments on an ongoing basis to provide liquidity. The instruments in which each Fund may invest include: (i) short-term obligations issued by the U.S. Government; (ii) negotiable certificates of deposit (“CDs”), fixed time deposits and bankers’ acceptances of U.S. and foreign banks and similar institutions; (iii) commercial paper rated at the date of purchase “Prime-1” by Moody’s Investors Service, Inc. or “A-1+” or “A-1” by Standard & Poor’s or, if unrated, of comparable quality as determined by Janus Capital; (iv) repurchase agreements; and (v) money market mutual funds. CDs are short-term negotiable obligations of commercial banks. Time deposits are non-negotiable deposits maintained in banking institutions for specified periods of time at stated interest rates. Banker’s acceptances are time drafts drawn on commercial banks by borrowers, usually in connection with international transactions.

Investment Company Securities

The Funds may invest in securities of other investment companies, subject to the provisions of the 1940 Act and any applicable SEC exemptive orders. Section 12(d)(1) of the 1940 Act prohibits a Fund from acquiring: (i) more than 3% of another investment company’s voting stock; (ii) securities of another investment company with a value in excess of 5% of a Fund’s total assets; or (iii) securities of such other investment company and all other investment companies owned by a Fund having a value in excess of 10% of the Fund’s total assets (the “Section 12(d)(1) Limits”). In addition, Section 12(d)(1) prohibits another investment company from selling its shares to a Fund if, after the sale: (i) the Fund owns more than 3% of the other investment company’s voting stock or (ii) the Fund and other investment companies, and companies controlled by them, own more than 10% of the voting stock of such other investment company. The Funds may invest their cash holdings in affiliated or non-affiliated money market funds as part of a cash sweep program. The Funds may purchase unlimited shares of affiliated or non-affiliated money market funds and of other funds managed by Janus Capital, whether registered or unregistered entities, as permitted by the 1940 Act and rules promulgated thereunder and/or an SEC exemptive order. To the extent the Funds invest in money market funds or other funds, the Funds will be subject to the same risks that investors experience when investing in such other funds. These risks may include the impact of significant fluctuations in assets as a result of the cash sweep program or purchase and redemption activity by affiliated or non-affiliated shareholders in such other funds. Additionally, to the extent that Janus Capital serves as the investment adviser to underlying funds or investment vehicles in which a Fund may invest, Janus Capital may have conflicting interests in fulfilling its fiduciary duties to both the Funds and the underlying funds or investment vehicles.

Investment companies may include index-based investments such as exchange-traded funds, which hold substantially all of their assets in investments representing specific indices. The main risk of investing in index-based investments is the same as investing in a portfolio of investments comprising the index. Index-based investments may not replicate exactly the

performance of their specific index because of transaction costs and because of the temporary unavailability of certain component securities of the index.

Some ETFs have obtained exemptive orders permitting other investment companies, such as the Funds, to acquire their securities in excess of the limits of Section 12(d)(1) the 1940 Act. The Funds may rely on this relief to invest in these ETFs in excess of the Section 12(d)(1) Limits. In addition, the Funds may invest in other investment companies in excess of the Section 12(d)(1) Limits in accordance with the provisions of Sections 12(d)(1)(F) or (G) of the 1940 Act, which provide certain exemptions from the Section 12(d)(1) Limits.

The Funds may invest in other exchange-traded funds, which are typically open-end investment companies that are traded on a national securities exchange. ETFs typically incur fees, such as investment advisory fees and other operating expenses that are separate from those of a Fund, which will be indirectly paid by the Fund. As a result, the cost of investing in a Fund may be higher than the cost of investing directly in ETFs and may be higher than other mutual funds that invest directly in stocks and bonds. Since ETFs are traded on an exchange at market prices that may vary from the net asset value of their underlying investments, there may be times when ETFs trade at a premium or discount. Similarly, because the value of ETF shares depends on the demand in the market, a Fund may not be able to purchase or sell an ETF at the most optimal time, which could adversely affect the Fund’s performance. In addition, ETFs that track particular indices may be unable to match the performance of such underlying indices due to the temporary unavailability of certain index securities in the secondary market or other factors, such as discrepancies with respect to the weighting of securities. The ETFs in which a Fund invests are subject to specific risks, depending on the investment strategy of the ETF. In turn, a Fund will be subject to substantially the same risks as those associated with direct exposure to the securities or commodities held by the ETF. Because the Funds may invest in a broad range of ETFs, such risks may include, but are not limited to, leverage risk, foreign exposure risk, and commodities risk.

Each Fund has obtained exemptive relief from the SEC permitting the Fund to sell, and other investment companies to acquire, shares in the Fund in excess of the limits imposed by Section 12(d)(1) of the 1940 Act. This exemptive relief is conditioned, among other things, on a Fund refraining from acquiring securities of an investment company, or certain private investment pools, in excess of the Section 12(d)(1) Limits. Consequently, if a Fund sells its shares to other investment companies in accordance with its exemptive relief, it will refrain from purchasing shares of ETFs, other registered investment companies, or private investment pools in excess of the limits imposed by Section 12(d)(1). Additionally, each Fund is permitted to invest in other registered investment companies beyond the limits set forth in Section 12(d)(1) subject to certain terms and conditions set forth in another exemptive order that the SEC has issued to Janus Capital and open-end investment companies advised by Janus Capital. If a Fund relies on this exemptive relief, however, other investment companies may not invest in the Fund beyond the statutory provisions of Section 12(d)(1). Notwithstanding these limitations, a Fund may still invest in other investment companies in excess of the Section 12(d)(1) Limits in order to engage in certain short-term cash management activities or to invest in a master fund pursuant to a Fund’s non-fundamental investment policy that permits the Fund to invest all of its assets in the securities of a single open-end management investment company with substantially the same fundamental investment objectives, policies, and limitations as the Fund.

Real Estate Investment Trusts (“REITs”)

Within the parameters of its specific investment policies, each Fund may invest in REITs. REITs are sometimes informally characterized as equity REITs, mortgage REITs, and hybrid REITs. In addition, a Fund may gain exposure to the real estate sector by investing in common, preferred and convertible securities of issuers in real estate-related industries. Investments in REITs and real estate-linked investments are subject to risks similar to those associated with direct ownership of real estate, including loss to casualty or condemnation, increases in property taxes and operating expenses, zoning law amendments, changes in interest rates, overbuilding and increased competition, variations in market value, fluctuations in rental income, possible environmental liabilities, regulatory limitations on rent, and other risks related to local or general economic conditions. Equity REITs generally experience these risks directly through fee or leasehold interests, whereas mortgage REITs generally experience these risks indirectly through mortgage interests, unless the mortgage REIT forecloses on the underlying real estate. Changes in interest rates may also affect the value of a Fund’s investment in REITs. For instance, during periods of declining interest rates, certain mortgage REITs may hold mortgages that the mortgagors elect to prepay, and prepayment may diminish the yield on securities issued by those REITs.

Certain REITs have relatively small market capitalizations, which may tend to increase the volatility of the market price of their securities. Furthermore, REITs are dependent upon specialized management skills, have limited diversification and are, therefore, subject to risks inherent in operating and financing a limited number of projects. REITs are also subject to heavy cash flow dependency, defaults by borrowers, and the possibility of failing to qualify for tax-free pass-through of income

under the Internal Revenue Code and to maintain exemption from the registration requirements of the 1940 Act. By investing in REITs indirectly through a Fund, a shareholder will bear not only his or her proportionate share of the expenses of a Fund, but also, indirectly, similar expenses of the REITs. In addition, REITs depend generally on their ability to generate cash flow to make distributions to shareholders.

Senior Securities

In general, the Funds may not issue any class of senior security, except within the limitations of the 1940 Act. These limitations allow a Fund to (i) borrow from banks, provided that immediately following any such borrowing there is an asset coverage of at least 300% (the “Asset Coverage Requirement”) for all Fund borrowings, and (ii) engage in trading practices which could be deemed to involve the issuance of a senior security, including but not limited to options, futures, forward contracts, and reverse repurchase agreements, provided that a Fund earmarks or segregates liquid assets in accordance with applicable SEC regulations and interpretations.

Futures and Options

The Funds may utilize exchange-traded futures and options contracts in order to manage uninvested cash and/or provide equity exposure for the Funds without having to purchase an underlying security.

Futures contracts generally provide for the future sale by one party and purchase by another party of a specified commodity at a specified future time and at a specified price. Stock index futures contracts are settled daily with a payment by one party to the other of a cash amount based on the difference between the level of the stock index specified in the contract from one day to the next. Futures contracts are standardized as to maturity date and underlying instrument and are traded on futures exchanges. Futures traders are required to make a good faith margin deposit in cash or U.S. government securities with a broker or custodian to initiate and maintain open positions in futures contracts. A margin deposit is intended to assure completion of the contract (delivery or acceptance of the underlying commodity or payment of the cash settlement amount) if it is not terminated prior to the specified delivery date. Brokers may establish deposit requirements which are higher than the exchange minimums. Futures contracts are customarily purchased and sold on margin deposits which may range upward from less than 5% of the value of the contract being traded. After a futures contract position is opened, the value of the contract is marked-to-market daily. If the futures contract price changes to the extent that the margin on deposit does not satisfy margin requirements, payment of additional “variation” margin will be required. Conversely, a change in the contract value may reduce the required margin, resulting in a repayment of excess margin to the contract holder. Variation margin payments are made to and from the futures broker for as long as the contract remains open. In such case, a Fund would expect to earn interest income on its margin deposits. Closing out an open futures position is done by taking an opposite position (“buying” a contract which has previously been “sold,” or “selling” a contract previously “purchased”) in an identical contract to terminate the position. Brokerage commissions are incurred when a futures contract position is opened or closed.

The Funds may use exchange-traded futures and options, together with positions in cash and money market instruments, to simulate full investment in the Underlying Index. Under such circumstances, Janus Capital may seek to utilize other instruments that it believes to be correlated to the Underlying Index components or a subset of the components.

An option on a futures contract, as contrasted with the direct investment in such a contract, gives the purchaser the right, in return for the premium paid, to assume a position in the underlying futures contract at a specified exercise price at any time prior to the expiration date of the option. Upon exercise of an option, the delivery of the futures position by the writer of the option to the holder of the option will be accompanied by delivery of the accumulated balance in the writer’s futures margin account that represents the amount by which the market price of the futures contract exceeds (in the case of a call) or is less than (in the case of a put) the exercise price of the option on the futures contract. The potential for loss related to the purchase of an option on a futures contract is limited to the premium paid for the option plus transaction costs. Because the value of the option is fixed at the point of purchase, there are no daily cash payments by the purchaser to reflect changes in the value of the underlying contract; however, the value of the option changes daily and that change would be reflected in the NAV of the Fund. The potential for loss related to writing call options on equity securities or indices is unlimited. The potential for loss related to writing put options is limited only by the aggregate strike price of the put option less the premium received.

The Funds may purchase and write put and call options on futures contracts that are traded on a U.S. exchange in anticipation of the purchase of securities, and may enter into closing transactions with respect to such options to terminate existing positions. There is no guarantee that such closing transactions can be effected.

Restrictions on the Use of Futures Contracts and Options on Futures Contracts

The Funds do not currently intend to, but may in the future, file a claim for exemption with the Commodity Futures Trading Commission (“CFTC”) on behalf of the Funds, so that neither the Funds nor the Trust are deemed to be a “commodity pool” or “commodity pool operator” (“CPO”), respectively, under the Commodity Exchange Act (“CEA”), and they are not subject to registration or regulation as such under the CEA. Janus Capital is not deemed to be a “commodity trading advisor” with respect to its services as an investment adviser to a Fund. In February 2012, however, the CFTC adopted certain regulatory changes that will subject the adviser of an investment company to registration with the CFTC as a CPO if the investment company is unable to comply with certain trading and marketing limitations.

With respect to investments in swap transactions, commodity futures, commodity options or certain other derivatives used for purposes other than bona fide hedging purposes, an investment company must meet one of the following tests under the amended regulations in order to claim an exemption from being considered a “commodity pool” or CPO. First, the aggregate initial margin and premiums required to establish an investment company’s positions in such investments may not exceed five percent (5%) of the liquidation value of the investment company’s portfolio (after accounting for unrealized profits and unrealized losses on any such investments). Alternatively, the aggregate net notional value of such instruments, determined at the time of the most recent position established, may not exceed one hundred percent (100%) of the liquidation value of the investment company’s portfolio (after accounting for unrealized profits and unrealized losses on any such positions). In addition to meeting one of the foregoing trading limitations, the investment company may not market itself as a commodity pool or otherwise as a vehicle for trading in the commodity futures, commodity options or swaps and derivatives markets. In the event that Janus Capital were required to register as a CPO with respect to a Fund, the disclosure and operations of the Fund would need to comply with all applicable CFTC regulations. Compliance with these additional registration and regulatory requirements would increase operational expenses. Other potentially adverse regulatory initiatives could also develop.

Market Events

The financial crisis in both the U.S. and global economies over the past several years has resulted, and may continue to result, in a significant decline in the value and liquidity of many securities of issuers worldwide in the equity and fixed-income/credit markets. In response to the crisis, the United States and certain foreign governments, along with the U.S. Federal Reserve and certain foreign central banks, took steps to support the financial markets. The withdrawal of this support, a failure of measures put in place to respond to the crisis, or investor perception that such efforts were not sufficient could each negatively affect financial markets generally, and the value and liquidity of specific securities. In addition, policy and legislative changes in the United States and in other countries continue to impact many aspects of financial regulation. The effect of these changes on the markets, and the practical implications for market participants, including the Funds, may not be fully known for some time. As a result, it may also be unusually difficult to identify both investment risks and opportunities, which could limit or preclude each Fund’s ability to achieve its investment objective. Therefore, it is important to understand that the value of your investment may fall, sometimes sharply, and you could lose money.

The enactment of the Dodd-Frank Act provided for widespread regulation of financial institutions, consumer financial products and services, broker-dealers, over-the-counter derivatives, investment advisers, credit rating agencies, and mortgage lending, which expanded federal oversight in the financial sector, including the investment management industry. Many provisions of the Dodd-Frank Act remain pending and will be implemented through future rulemaking. Therefore, the ultimate impact of the Dodd-Frank Act and the regulations under the Dodd-Frank Act on the Funds and the investment management industry as a whole is not yet certain.

Natural Disasters and Extreme Weather Conditions

Certain areas of the world have historically been prone to and economically sensitive to environmental events such as, but not limited to, hurricanes, earthquakes, typhoons, flooding, tidal waves, tsunamis, erupting volcanoes, wildfires or droughts, tornadoes, mudslides, or other weather-related phenomena. Such disasters, and the resulting physical or economic damage, could have a severe and negative impact on a Fund’s investment portfolio and, in the longer term, could impair the ability of issuers in which the Fund invests to conduct their businesses as they would under normal conditions. Adverse weather conditions may also have a particularly significant negative effect on issuers in the agricultural sector and on insurance companies that insure against the impact of natural disasters.

Tax Risks

As with any investment, you should consider how your investment in shares of a Fund will be taxed. The tax information in the Prospectuses and this SAI is provided as general information. You should consult your own tax professional about the tax

consequences of an investment in shares of a Fund. Refer to the “Income Dividends, Capital Gain Distributions, and Tax Status” section of this Statement of Additional Information for additional information regarding Fund taxation.

INFORMATION ABOUT EACH UNDERLYING INDEX PROVIDER AND DISCLAIMERS

Each Fund will attempt to correspond generally, before fees and expenses, to the performance of its respective Underlying Index.

Janus Index & Calculation Services LLC (“Janus Index Services” or “Index Provider”) is affiliated with each Fund and Janus Capital. This affiliation may create potential conflicts for Janus Index Services as it may have an interest in the performance of each Fund, which could motivate it to alter the index methodology for each Underlying Index. Janus Index Services has adopted procedures that it believes are reasonably designed to mitigate these and other potential conflicts.

Each Fund is entitled to use its respective Underlying Index pursuant to a licensing agreement with Janus Index Services and Janus Capital. Janus Capital pays a licensing fee to the Index Provider out of the management fee.

The only relationship that Janus Index Services has with each Fund, Janus Capital, or ALPS Distributors, Inc., the distributor of each Fund in connection with each Fund is that Janus Index Services has licensed certain of its intellectual property, including the determination of the component stocks of the Underlying Index and the name of the Underlying Index. The Underlying Index is selected and calculated without regard to Janus Capital, ALPS Distributors, Inc., or owners of a Fund. Janus Index Services has no obligation to take the specific needs of Janus Capital, ALPS Distributors, Inc., or owners of a Fund into consideration in the determination and calculation of the Underlying Index. Janus Index Services is not responsible for and has not participated in the determination of pricing or the timing of the issuance or sale of the shares of a Fund or in the determination or calculation of the net asset value of a Fund. Janus Index Services has no obligation or liability in connection with the administration or trading of a Fund.

ALTHOUGH JANUS INDEX SERVICES SHALL OBTAIN INFORMATION FOR INCLUSION IN OR FOR USE IN THE CALCULATION OF THE INDICES FROM SOURCES WHICH IT CONSIDERS RELIABLE, IT DOES NOT GUARANTEE THE QUALITY, ACCURACY AND/OR THE COMPLETENESS OF EITHER UNDERLYING INDEX OR ANY DATA INCLUDED THEREIN AND SHALL HAVE NO LIABILITY FOR ERRORS OR OMISSIONS OF ANY KIND RELATED TO EITHER UNDERLYING INDEX OR DATA. JANUS INDEX SERVICES MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY JANUS CAPITAL, OWNERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF EITHER UNDERLYING INDEX OR ANY DATA INCLUDED THEREIN IN CONNECTION WITH THE RIGHTS LICENSED TO JANUS CAPITAL FOR ANY OTHER USE. JANUS INDEX SERVICES MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO EITHER UNDERLYING INDEX OR ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL IT HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

Janus Capital does not guarantee the accuracy and/or the completeness of either Underlying Index or any data included therein, and Janus Capital shall have no liability for any errors, omissions or interruptions therein. Janus Capital makes no warranty, express or implied, as to results to be obtained by a Fund, owners of the shares of a Fund or any other person or entity from the use of either Underlying Index or any data included therein. Janus Capital makes no express or implied warranties, and expressly disclaims all warranties of merchantability or fitness for a particular purpose or use with respect to either Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall Janus Capital have any liability for any special, punitive, direct, indirect or consequential damages (including lost profits) arising out of matters relating to the use of either Underlying Index even if notified of the possibility of such damages.

Janus Capital and Janus Capital’s logo are service marks of Janus Capital. All other trademarks, service marks or registered trademarks are the property of their respective owners. These marks have been licensed for use by Janus Index Services.

PORTFOLIO TURNOVER

As of the date of this SAI, portfolio turnover rates are not available for the Funds because each Fund is new.

AVAILABILITY OF PORTFOLIO HOLDINGS INFORMATION

The Investment Company Holdings Disclosure Policies and Procedures adopted by the Funds’ Trustees are designed to ensure that a Fund’s portfolio holdings information is disclosed in a manner that (i) is consistent with applicable legal requirements and in the best interest of the Fund’s shareholders; (ii) does not put the interests of Janus Capital, ALPS Distributors, Inc., or any affiliated person of Janus Capital or ALPS Distributors, Inc., above those of Fund shareholders; (iii) does not advantage any current or prospective Fund shareholders over any other current or prospective Fund shareholders, except to the extent that certain entities (as described below) may receive portfolio holdings information not available to other current or prospective Fund shareholders in connection with the dissemination of Creation Units; and (iv) does not provide selective access to portfolio holdings information except pursuant to the procedures outlined below and to the extent appropriate confidentiality arrangements limiting the use of such information are in effect. The “entities” referred to in sub-section (iii) above are generally limited to National Securities Clearing Corporation members, subscribers to various fee-based subscription services, Authorized Participants, and other institutional market participants and entities that provide information for transactional services.

•

Disclosure of Portfolio Holdings in Accordance with SEC Exemptive Relief. Each business day, a Fund’s portfolio holdings information is provided to ALPS Distributors, Inc. or other agent for dissemination through the facilities of the National Securities Clearing Corporation and/or other fee-based subscription services to National Securities Clearing Corporation members and/or subscribers to entities that publish and/or analyze such information in connection with the process of purchasing or redeeming Creation Units or trading shares of the Fund in the secondary market. This information typically reflects a Fund’s anticipated holdings on the following business day. In addition, on each business day before commencement of trading in shares on the NASDAQ, a Fund will disclose on janus.com/etfs the identities and quantities of each portfolio position held by the Fund that will form the basis for the Fund’s calculation of the NAV per share at the end of the business day.

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Disclosure of Portfolio Holdings as Required by Applicable Law. Each Fund is also required to disclose its complete holdings in the quarterly holdings report on Form N-Q within 60 days of the end of the first and third fiscal quarters, and in the annual report and semiannual report to Fund shareholders. These reports (i) are available on the SEC’s website at http://www.sec.gov; (ii) may be reviewed and copied at the SEC’s Public Reference Room in Washington, D.C. (information on the Public Reference Room may be obtained by calling 1-800-SEC-0330); and (iii) are available without charge, upon request, by calling a Janus representative at 1-800-525-0020.

Daily access to information concerning each Fund’s portfolio holdings is permitted (i) to certain personnel of those service providers that are involved in portfolio management and in providing administrative, operational, risk management, or other support to portfolio management; and (ii) to other personnel of Janus Capital, ALPS Distributors, Inc. and its affiliates, and the administrator, custodian, and fund accountant who deal directly with, or assist in, functions related to investment management, distribution, administration, custody, securities lending, and fund accounting, as may be necessary to conduct business in the ordinary course in a manner consistent with federal securities laws and regulations thereunder.

Portfolio holdings information made available in connection with the creation/redemption process may be provided to other entities that provide services to a Fund in the ordinary course of business after it has been disseminated to the National Securities Clearing Corporation. From time to time, information concerning portfolio holdings other than portfolio holdings information made available in connection with the creation/redemption process, as discussed above, may be provided to other entities that provide services to a Fund, including rating or ranking organizations, in the ordinary course of business, no earlier than one business day following the date of the information.

Nonpublic portfolio holdings information may be disclosed to certain third parties upon a good faith determination made by Janus Capital’s Chief Compliance Officer that a Fund has a legitimate business purpose for such disclosure and the recipient agrees to maintain confidentiality. The Chief Compliance Officer reports to the Funds’ Trustees regarding material compliance matters with respect to the portfolio holdings disclosure policies and procedures.

Under extraordinary circumstances, Janus Capital’s Chief Compliance Officer or a designee has the authority to waive one or more provisions of, or make exceptions to, the Investment Company Holdings Disclosure Policies and Procedures when in the best interest of a Fund and when such waiver or exception is consistent with federal securities laws and applicable fiduciary duties. The frequency with which portfolio holdings are disclosed, as well as the lag time associated with such disclosure, may vary as deemed appropriate under the circumstances.

Investment adviser

INVESTMENT ADVISER – JANUS CAPITAL MANAGEMENT LLC

As stated in the Prospectuses, the Funds have an Investment Advisory Agreement with Janus Capital Management LLC, 151 Detroit Street, Denver, Colorado 80206-4805. Janus Capital is a direct subsidiary of Janus Capital Group Inc. (“JCGI”), a publicly traded company with principal operations in financial asset management businesses. JCGI owns approximately 95% of Janus Capital, with the remaining 5% held by Janus Management Holdings Corporation.

The Funds’ Advisory Agreement will be in effect for an initial term of two years and from year to year thereafter so long as such continuance is approved at least annually by the vote of a majority of the Funds’ Trustees who are not parties to the Advisory Agreement or “interested persons” (as defined by the 1940 Act) of any such party (the “Independent Trustees”), and by either the Funds’ Trustees or the affirmative vote of a majority of the outstanding voting securities of each Fund. The Advisory Agreement: (i) may be terminated, without the payment of any penalty, by a Fund’s Trustees, or the vote of at least a majority of the outstanding voting securities of a Fund, or Janus Capital, on 60 days’ advance written notice; (ii) terminates automatically in the event of its assignment; and (iii) generally, may not be amended without the approval by vote of a majority of the Trustees of the affected Fund, including a majority of the Independent Trustees, and, to the extent required by the 1940 Act, the affirmative vote of a majority of the outstanding voting securities of that Fund.

The Advisory Agreement provides that Janus Capital will furnish continuous advice and recommendations concerning the Funds’ investments, provide office space for the Funds, and certain other advisory-related services. Pursuant to the Advisory Agreement, under the unitary fee structure, each Fund pays Janus Capital a “Management Fee” in return for providing certain investment advisory, supervisory, and administrative services to the Funds. The fee structure is designed to pay substantially all of the Funds’ expenses. However, each Fund bears other expenses which are not covered under the Management Fee, such as distribution fees (if any), brokerage expenses or commissions, interest, dividends, taxes, litigation expenses, acquired fund fees and expenses (if any), and extraordinary expenses.

Janus Capital has received an exemptive order from the SEC that permits Janus Capital, subject to the approval of the Trustees, to appoint or replace certain subadvisers to manage all or a portion of a Fund’s assets and enter into, amend, or terminate a subadvisory agreement with certain subadvisers without obtaining shareholder approval (a “manager-of-managers structure”). The manager-of-managers structure applies to subadvisers that are not affiliated with the Trust or Janus Capital (“non-affiliated subadvisers”), as well as any subadviser that is an indirect or direct “wholly-owned subsidiary” (as such term is defined by the 1940 Act) of Janus Capital or of another company that, indirectly or directly, wholly owns Janus Capital (collectively, “wholly-owned subadvisers”).

Pursuant to the order, Janus Capital, with the approval of the Trustees, has the discretion to terminate any subadviser and allocate and reallocate a Fund’s assets among Janus Capital and any other non-affiliated subadvisers or wholly-owned subadvisers (including terminating a non-affiliated subadviser and replacing it with a wholly-owned subadviser). To the extent that a Fund’s assets are allocated to one or more subadvisers, Janus Capital, subject to oversight and supervision by the Trustees, would have responsibility to oversee such subadviser to a Fund and to recommend for approval by the Trustees, the hiring, termination, and replacement of a subadviser for a Fund. The order also permits a Fund to disclose subadvisers’ fees only in the aggregate. In the event that Janus Capital hires a subadviser pursuant to the manager-of-managers structure, the affected Janus fund would provide shareholders with information about the subadviser and subadvisory agreement within 90 days.

The Trustees and the initial shareholder of each Fund have approved the use of a manager-of-managers structure for the Fund.

Janus Capital also provides certain administration services necessary for the operation of each Fund, including, but not limited to, blue sky registration and monitoring services, and preparation of prospectuses.

A discussion regarding the basis for the Trustees’ approval of the Funds’ Advisory Agreement will be included in each Fund’s next annual report (for the period ending October 31) or semiannual report (for the period ending April 30) to shareholders, following such approval. You can request the Funds’ annual or semiannual reports (as they become available), free of charge, by contacting your broker-dealer, plan sponsor, or financial intermediary, or by contacting a Janus representative at 1-877-335-2687. The reports are also available, free of charge, at janus.com/etfs.

The Funds pay a monthly Management Fee to Janus Capital for its services. The fee is based on the average daily net assets of each Fund and is calculated at the following annual rate.


		Contractual
	Average Daily Net	Management Fees (%)
Fund Name	Assets of Fund	(annual rate)
Janus Small Cap Growth Alpha ETF	All Asset Levels		0.50

Janus Small/Mid Cap Growth Alpha ETF	All Asset Levels		0.50

As of the date of this SAI, no Management Fees were paid because the Funds are new.

PAYMENTS TO FINANCIAL INTERMEDIARIES BY JANUS CAPITAL OR ITS AFFILIATES

From their own assets, Janus Capital or its affiliates may pay selected brokerage firms or other financial intermediaries for making a Fund available to their clients or otherwise distributing, promoting or marketing the Funds. Janus Capital or its affiliates may also make payments to intermediaries for information about transactions and holdings in a Fund, such as the amount of Fund shares purchased, sold or held through the intermediary and or its salespersons, the intermediary platform(s) on which shares are transacted and other information related to a Fund. Janus Capital or its affiliates may also make payments to intermediaries to eliminate or reduce trading commissions that the intermediary would otherwise charge its customers or its salespersons in connection with the purchase or sale of certain funds. Payment by Janus Capital or its affiliates to eliminate or reduce a trading commission creates an incentive for salespersons of the intermediary to sell the Janus funds over other funds for which a commission would be charged. The amount of these payments is determined from time to time by Janus Capital, may be substantial, and may differ for different intermediaries. Janus Capital may determine to make payments based on any number of factors or metrics. For example, Janus Capital may make payments at year-end and/or other intervals in a fixed amount, an amount based upon an intermediary’s services at defined levels, an amount based upon the total assets represented by funds subject to arrangements with the intermediary, or an amount based on the intermediary’s net sales of one or more funds in a year or other period, any of which arrangements may include an agreed-upon minimum or maximum payment, or any combination of the foregoing. Other factors may include, but are not limited to, the distribution capabilities of the intermediary, the overall quality of the relationship, expected gross and/or net sales generated by the relationship, redemption and retention rates of assets held through the intermediary, the willingness to cooperate with Janus Capital’s marketing efforts, access to sales personnel, and the anticipated profitability of sales through the institutional relationship. These factors and their weightings may differ from one intermediary to another and may change from time to time.

With respect to non-exchange-traded Janus funds, Janus Capital or its affiliates may pay fees, from their own assets, to selected brokerage firms, banks, financial advisors, retirement plan service providers, and other financial intermediaries that sell the Janus funds for distribution, marketing, promotional, or related services, and/or for providing recordkeeping, subaccounting, transaction processing, and other shareholder or administrative services (including payments for processing transactions via National Securities Clearing Corporation (“NSCC”) or other means) in connection with investments in the Janus funds. These fees are in addition to any fees that may be paid by the Janus funds for these types of services or other services. Shareholders investing through an intermediary should consider whether such arrangements exist when evaluating any recommendations from an intermediary.

In addition, Janus Capital or its affiliates may also share certain marketing expenses with intermediaries, or pay for or sponsor informational meetings, seminars, client awareness events, support for marketing materials, sales reporting, or business building programs for such intermediaries to raise awareness of the Janus funds. Janus Capital or its affiliates may also pay intermediaries for the development of technology platforms and reporting systems. Janus Capital or its affiliates may make payments to participate in intermediary marketing support programs which may provide Janus Capital or its affiliates with one or more of the following benefits: attendance at sales conferences, participation in meetings or training sessions, access to or information about intermediary personnel, use of an intermediary’s marketing and communication infrastructure, fund analysis tools, business planning and strategy sessions with intermediary personnel, information on industry- or platform-specific developments, trends and service providers, and other marketing-related services. Such payments may be in addition to, or in lieu of, the payments described above. These payments are intended to promote the sales of Janus funds and to reimburse financial intermediaries, directly or indirectly, for the costs that they or their salespersons incur in connection with educational seminars, meetings, and training efforts about the Janus funds to enable the intermediaries and their salespersons

to make suitable recommendations, provide useful services, and maintain the necessary infrastructure to make the Janus funds available to their customers.

The receipt of (or prospect of receiving) payments, reimbursements, and other forms of compensation described above may provide a financial intermediary and its salespersons with an incentive to favor sales of Janus funds’ shares over sales of other funds (or non-investment company investments), with respect to which the financial intermediary does not receive such payments or receives them in a lower amount. The receipt of these payments may cause certain financial intermediaries to elevate the prominence of the Janus funds within such financial intermediary’s organization by, for example, placement on a list of preferred or recommended funds and/or the provision of preferential or enhanced opportunities to promote the Janus funds in various ways within such financial intermediary’s organization.

The payment arrangements described above will not change the price an investor pays for shares nor the amount that a Janus fund receives to invest on behalf of the investor. You should consider whether such arrangements exist when evaluating any recommendations from an intermediary to purchase or sell shares of a Fund. Please contact your financial intermediary or plan sponsor for details on such arrangements.

ADDITIONAL INFORMATION ABOUT JANUS CAPITAL

Janus Capital acts as adviser to a number of mutual funds. In addition, it acts as subadviser for a number of private-label mutual funds and provides separate account advisory services for institutional accounts. Janus Capital may also manage its own proprietary accounts, as well as other pooled investment vehicles, such as hedge funds. Janus Capital has a fiduciary responsibility to manage all client accounts in a fair and equitable manner. As such, inves


Part A –		Prospectuses for: Janus Small Cap Growth Alpha ETF, Janus Small/Mid Cap Growth Alpha ETF, Janus Velocity Tail Risk Hedged Large Cap ETF, Janus Velocity Volatility Hedged Large Cap ETF

Part B –		Statements of Additional Information for: Janus Alpha ETFs, Janus Velocity Tail Risk Hedged Large Cap ETF, Janus Velocity Volatility Hedged Large Cap ETF

Part C –		Other Information


Classification, Investment Policies and Restrictions, and Investment Strategies and Risks		2

Investment Adviser		14

Custodian, Transfer Agent, and Certain Affiliations		20

Portfolio Transactions and Brokerage		21

Shares of the Trust		23
Net Asset Value Determination		23
Creation and Redemption of Creation Units		24

Income Dividends, Capital Gains Distributions, and Tax Status		32

Trustees and Officers		35

Principal Shareholders		41

Miscellaneous Information		42
Shares of the Trust		42
Shareholder Meetings		42
Voting Rights		42
Master/Feeder Option		43
Independent Registered Public Accounting Firm		43
Registration Statement		43

Financial Statements		44


Fund summary
Janus Small Cap Growth Alpha ETF		2

Additional information about the Fund
Fees and expenses		6
Additional investment strategies and general portfolio policies		6
Risks of the Fund		7

Management of the Fund
Investment adviser		10
Management expenses		10
Investment personnel		11

Other information		12

Dividends, distributions, and taxes		13

Shareholder’s guide
Pricing of fund shares		15
Distribution and servicing fees		15
Payments to financial intermediaries by Janus Capital or its affiliates		16
Purchasing and selling shares		17
Excessive trading		19
Shareholder communications		19

Financial highlights		21