497

Summary of Functions

Members

(Independent Trustees)

Number of Meetings Held during Last Fiscal Year Ended October 31, 2021

Audit and Pricing Committee

Reviews the financial reporting process, the system of internal controls over financial reporting, disclosure controls and procedures, and the audit process. The Committee’s review of the audit process includes, among other things, the appointment, compensation, and oversight of the Trust’s independent auditor and preapproval of all audit and nonaudit services.

Oversees the Adviser as valuation designee and reviews reports on fair valuation determinations and valuation methodologies regarding securities and investments held by the Fund pursuant to valuation procedures established by the Adviser and approved by the Board of Trustees, reviews other matters related to the pricing of securities, and approves changes to the valuation procedures.

Jeffrey B. Weeden

(Chair)

Maureen T. Upton

Clifford J. Weber

497 1 d387170d497.htm 497 497

Janus Detroit Street Trust

Janus Henderson Small Cap Growth Alpha ETF

Janus Henderson Small/Mid Cap Growth Alpha ETF

(each a “Fund” and collectively, the “Funds”)

Supplement dated September 1, 2022

to Currently Effective Funds’ Prospectuses

and Statement of Additional Information (“SAI”)

Effective immediately, the prospectus for each Fund is amended as follows:

1. Under “Pricing of Fund Shares” in the Shareholder’s Guide section of each Fund’s prospectus, the following information replaces the corresponding information in its entirety:

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 trading session of the New York Stock Exchange (“NYSE”) (normally 4:00 p.m. New York time) each day that the NYSE is open. 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 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 the Adviser pursuant to Rule 2a-5 under the Investment Company Act of 1940 (“1940 Act”) and approved by and subject to the oversight of the Trustees (“Valuation Procedures”). To the extent available, equity securities (including shares of exchange-traded funds) are generally valued at readily available market quotations, which are (i) the official close prices or (ii) last sale prices on the primary market or exchange in which the securities trade. Most fixed-income securities are typically valued using an evaluated bid price supplied by an Adviser-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 by the Adviser pursuant to the Valuation 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 valuation 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 methodologies employed when fair valuing securities may change from time to time. Because fair value pricing involves subjective judgments, it is possible that the fair value determination for a security may be different than the value that could be realized when selling that security.

The value of the securities of mutual funds held by the Funds, 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 valuation and the effects of using fair valuation.

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

Effective immediately, the Funds’ SAI is amended as follows:

1. Under “Net Asset Value Determination” in the Shares of the Trust section of the Funds’ SAI, the following information replaces the corresponding information in its entirety:

As stated in each Fund’s Prospectus, the net asset value (“NAV”) of the shares of a Fund is determined once each day the New York Stock Exchange (the “NYSE”) is open, as of the close of its trading session (normally 4:00 p.m., New York time, Monday through Friday). The per share NAV of a Fund is computed by dividing the net assets by the number of a Fund’s shares outstanding.

Securities held by a Fund are valued in accordance with policies and procedures established by the Adviser pursuant to Rule 2a-5 under the 1940 Act and approved by and subject to the oversight of the Trustees (the “Valuation Procedures”). In determining NAV, equity securities traded on a domestic securities exchange are generally valued at the readily available market quotations, which are (i) the official close prices or (ii) last sale prices on the primary market or exchange in which the securities trade. If such price is lacking for the trading period immediately preceding the time of determination, such securities are valued at their current bid price. If applicable, equity securities that are traded on a foreign exchange are generally valued at the closing prices on such markets. In the event that there is not current trading volume on a particular security in such foreign exchange, the bid price from the primary exchange is generally used to value the security. Securities that are traded on the over-the-counter markets are generally valued at their closing or latest bid prices as available. Foreign securities and currencies are converted to U.S. dollars using the applicable exchange rate in effect at the close of the London Stock Exchange. The Adviser will determine the market value of individual securities held by it by using prices provided by one or more Adviser-approved professional pricing services or, as needed, by obtaining market quotations from independent broker-dealers. Most debt securities are valued in accordance with the evaluated bid price supplied by the pricing service that is intended to reflect market value. The evaluated bid price supplied by the pricing service is an evaluation that may consider factors such as security prices, yields, maturities, and ratings. Certain short-term securities maturing within 60 days or less may be valued on an amortized cost basis.

Securities for which market quotations or evaluated prices are not readily available or are deemed unreliable are valued at fair value determined in good faith by the Adviser pursuant to the Valuation Procedures. Circumstances in which fair valuation may be utilized 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 nonsignificant event such as a market closing early or not opening, or a security trading halt; and (iv) pricing of a nonvalued security and a restricted or nonpublic security. 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.

Each Fund calculates its NAV per share, and therefore effects sales, redemptions, and repurchases of its shares, as of the close of the NYSE once each day on which the NYSE is open. Such calculation may not take place contemporaneously with the determination of the prices of the foreign portfolio securities used in such calculation. If an event that is expected to affect the value of a portfolio security occurs after the close of the principal exchange or market on which that security is traded, and before the close of the NYSE, then that security may be valued in good faith under the Valuation Procedures.

2. Under “Committees of the Board” in the Trustees and Officers section of the Funds’ SAI, the following information replaces the corresponding information in its entirety:

Please retain this Supplement with your records.

Janus Detroit Street Trust

Janus Henderson International Sustainable Equity ETF

Janus Henderson Net Zero Transition Resources ETF

Janus Henderson Sustainable Corporate Bond ETF

Janus Henderson Sustainable & Impact Core Bond ETF

Janus Henderson U.S. Sustainable Equity ETF

(each a “Fund” and collectively, the “Funds”)

Supplement dated September 1, 2022

to Currently Effective Funds’ Prospectuses

and Statements of Additional Information (“SAIs”)

Effective immediately, the prospectus for each Fund is amended as follows:

1. Under “Pricing of Fund Shares” in the Shareholder’s Guide section of each Fund’s prospectus, the following information replaces the corresponding information in its entirety:

The per share NAV of each 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. Each Fund’s NAV is calculated as of the close of the trading session of the New York Stock Exchange (“NYSE”) (normally 4:00 p.m. New York time) each day that the NYSE is open. However, the NAV may still be calculated if trading on the NYSE is restricted, provided there is sufficient pricing information available for a Fund to value its securities, or as permitted by the SEC. Foreign securities held by a Fund, as applicable, may be traded on days and at times when the NYSE is closed and the NAV is therefore not calculated. Accordingly, the value of a 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 each Fund are valued in accordance with policies and procedures established by the Adviser pursuant to Rule 2a-5 under the Investment Company Act of 1940 (“1940 Act”) and approved by and subject to the oversight of the Trustees (“Valuation Procedures”). To the extent available, equity securities (including shares of exchange-traded funds) are generally valued at readily available market quotations, which are (i) the official close prices or (ii) last sale prices on the primary market or exchange in which the securities trade. Most fixed-income securities are typically valued using an evaluated bid price supplied by an Adviser-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 by the Adviser pursuant to the Valuation 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 valuation 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 methodologies employed when fair valuing securities may change from time to time. Because fair value pricing involves subjective judgments, it is possible that the fair value determination for a security may be different than the value that could be realized when selling that security.

The value of the securities of mutual funds held by each 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 valuation and the effects of using fair valuation.

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

Effective immediately, each Fund’s SAI is amended as follows:

1. Under “Net Asset Value Determination” in the Shares of the Trust section of the Funds’ SAI, the following information replaces the corresponding information in its entirety:

As stated in each Fund’s Prospectus, the net asset value (“NAV”) of the shares of each Fund are determined once each day the New York Stock Exchange (the “NYSE”) is open, as of the close of its trading session (normally 4:00 p.m., New York time, Monday through Friday). The per share NAV of a Fund is computed by dividing the net assets by the number of a Fund’s shares outstanding.

Securities held by each Fund are valued in accordance with policies and procedures established by the Adviser pursuant to Rule 2a-5 under the 1940 Act and approved by and subject to the oversight of the Trustees (the “Valuation Procedures”). In determining NAV, equity securities traded on a domestic securities exchange are generally valued at the readily available market quotations, which are (i) the official close prices or (ii) last sale prices on the primary market or exchange in which the securities trade. If such price is lacking for the trading period immediately preceding the time of determination, such securities are valued at their current bid price. If applicable, equity securities that are traded on a foreign exchange are generally valued at the closing prices on such markets. In the event that there is not current trading volume on a particular security in such foreign exchange, the bid price from the primary exchange is generally used to value the security. Securities that are traded on the over-the-counter markets are generally valued at their closing or latest bid prices as available. Foreign securities and currencies are converted to U.S. dollars using the applicable exchange rate in effect at the close of the London Stock Exchange. The Adviser will determine the market value of individual securities held by it by using prices provided by one or more Adviser-approved professional pricing services or, as needed, by obtaining market quotations from independent broker-dealers. Most debt securities are valued in accordance with the evaluated bid price supplied by the pricing service that is intended to reflect market value. The evaluated bid price supplied by the pricing service is an evaluation that may consider factors such as security prices, yields, maturities, and ratings. Certain short-term securities maturing within 60 days or less may be valued on an amortized cost basis.

2. Under “Committees of the Board” in the Trustees and Officers section of each Fund’s SAI, the following information replaces the corresponding information in its entirety:

Please retain this Supplement with your records.

Janus Detroit Street Trust

Janus Henderson AAA CLO ETF

Janus Henderson B-BBB CLO ETF

Janus Henderson Mortgage-Backed Securities ETF

Janus Henderson Short Duration Income ETF

Janus Henderson U.S. Real Estate ETF

(each a “Fund” and collectively, the “Funds”)

Supplement dated September 1, 2022

to Currently Effective Funds’ Prospectuses

and the Statements of Additional Information (“SAIs”)

Effective immediately, the prospectus for each Fund is amended as follows:

1. Under “Pricing of Fund Shares” in the Shareholder’s Guide section of each Fund’s prospectus, the following information replaces the corresponding information in its entirety:

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 valuation and the effects of using fair valuation.

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

Effective immediately, the prospectus for Janus Henderson Short Duration Income ETF, is amended as follows:

1. Under “Additional Investment Strategies and General Portfolio Policies” in the Additional Information about the Fund section, of the Fund’s prospectus, the following information is added:

ESG Integration

The portfolio managers integrate environmental, social, and governance (“ESG”) factors by incorporating ESG information into the Fund’s investment process. The portfolio managers focus on the ESG factors they consider most likely to have a material impact on the financial performance of the issuers in the Fund’s portfolio, which includes identifying material ESG risk factors attributable to a particular sector, industry, or issuer. The portfolio managers believe that an issuer’s ESG practices may have an impact, positive or negative, on the issuer’s long-term financial performance, and may engage with an issuer’s management to encourage improved ESG practices. ESG factors are one of many considerations in the investment decision-making process and may not be determinative in deciding to include or exclude an investment from the portfolio.

2. Under “Risks of the Fund” in the Additional Information about the Fund section, of the Fund’s prospectus, the following information is added:

ESG Integration Risk. The portfolio managers integrate ESG factors by incorporating ESG information into the Fund’s investment process. As a result of either positive investment selection or avoidance, the Fund may be overweight, underweight or have no exposure to certain industries, sectors, or regions relative to its benchmark index and/or similar funds that do not consider ESG factors. This may in turn cause the Fund to underperform relative to its benchmark index or similar funds that do not consider ESG factors. In addition, information related to ESG factors provided by issuers and third parties, upon which the portfolio managers may rely, continues to develop, and may be incomplete, inaccurate, use different methodologies or be applied differently across issuers and industries.

Effective immediately, each Fund’s SAI is amended as follows:

1. Under “Net Asset Value Determination” in the Shares of the Trust section of the Funds’ SAI, the following information replaces the corresponding information in its entirety:

As stated in the Fund’s Prospectus, the net asset value (“NAV”) of the shares of the Fund is determined once each day the New York Stock Exchange (the “NYSE”) is open, as of the close of its trading session (normally 4:00 p.m., New York time, Monday through Friday). The per share NAV of the Fund is computed by dividing the net assets by the number of the Fund’s shares outstanding.

Securities held by the Fund are valued in accordance with policies and procedures established by the Adviser pursuant to Rule 2a-5 under the 1940 Act and approved by and subject to the oversight of the Trustees (the “Valuation Procedures”). In determining NAV, equity securities traded on a domestic securities exchange are generally valued at the readily available market quotations, which are (i) the official close prices or (ii) last sale prices on the primary market or exchange in which the securities trade. If such price is lacking for the trading period immediately preceding the time of determination, such securities are valued at their current bid price. If applicable, equity securities that are traded on a foreign exchange are generally valued at the closing prices on such markets. In the event that there is not current trading volume on a particular security in such foreign exchange, the bid price from the primary exchange is generally used to value the security. Securities that are traded on the over-the-counter markets are generally valued at their closing or latest bid prices as available. Foreign securities and currencies are converted to U.S. dollars using the applicable exchange rate in effect at the close of the London Stock Exchange. The Adviser will determine the market value of individual securities held by it by using prices provided by one or more Adviser-approved professional pricing services or, as needed, by obtaining market quotations from independent broker-dealers. Most debt securities are valued in accordance with the evaluated bid price supplied by the pricing service that is intended to reflect market value. The evaluated bid price supplied by the pricing service is an evaluation that may consider factors such as security prices, yields, maturities, and ratings. Certain short-term securities maturing within 60 days or less may be valued on an amortized cost basis.

The Fund calculates its NAV per share, and therefore effects sales, redemptions, and repurchases of its shares, as of the close of the NYSE once each day on which the NYSE is open. Such calculation may not take place contemporaneously with the determination of the prices of the foreign portfolio securities used in such calculation. If an event that is expected to affect the value of a portfolio security occurs after the close of the principal exchange or market on which that security is traded, and before the close of the NYSE, then that security may be valued in good faith under the Valuation Procedures.

2. Under “Committees of the Board” in the Trustees and Officers section of each Fund’s SAI, the following information replaces the corresponding information in its entirety:

Please retain this Supplement with your records.