Janus Henderson Small Cap Value Fund (JSCVX) N-14/ARegistration statement for investment companies business combination (amended)

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As filed with the Securities and Exchange Commission on March 8, 2023

Securities Act File No. 333-269480

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-14

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

(Check appropriate box or boxes)

Janus Investment Fund

(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)

(303) 333-3863

(Area Code and Telephone Number)

Abigail Murray

151 Detroit Street

Denver, Colorado 80206-4805

(Name and Address of Agent for Service)

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

The titles of the securities being registered are:

Class A, C, D, I, N, R, S and T Shares of Janus Henderson Overseas Fund.

No filing fee is required because an indefinite number of shares of beneficial interest with $0.01 par value of the Registrant have previously been registered pursuant to Section 24(f) of the Investment Company Act of 1940, as amended.

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For shareholders of:

Janus Henderson International Opportunities Fund

March 8, 2023

Dear Shareholder:

We wanted to inform you, as a shareholder of Janus Henderson International Opportunities Fund, that Janus Henderson Investors US LLC (referred to herein as “Janus Henderson” or, the “Adviser”) recommended, and the Board of Trustees of your Fund has approved, the Adviser’s proposal to merge Janus Henderson International Opportunities Fund into Janus Henderson Overseas Fund, effective on or about June 2, 2023, or as soon as practicable thereafter. Janus Henderson believes that Janus Henderson International Opportunities Fund shareholders may benefit from being shareholders of one larger combined international equity fund, creating the potential for broader asset growth and a more stable asset base while realizing portfolio management and operational efficiencies. Additionally, Janus Henderson believes that Janus Henderson International Opportunities Fund shareholders may benefit from the centralized research approach employed by Janus Henderson Overseas Fund, which differs from the multi-sub-portfolio approach employed by International Opportunities Fund, wherein underlying sleeve sub-portfolio managers focus on their highest conviction ideas. This merger is subject to approval by shareholders of Janus Henderson International Opportunities Fund. If the merger is approved, and other closing conditions are satisfied or waived, you will receive the same class of shares of Janus Henderson Overseas Fund that you hold in Janus Henderson International Opportunities Fund as of the merger date. The Funds have similar investment objectives, investment policies, and principal investment strategies. Each Fund pursues its investment objective by primarily investing in securities of companies outside of the United States. The Funds may invest in securities of all market capitalizations and may have significant exposure to emerging markets.

The merger is designed to qualify as a tax-free merger, so you should generally not realize a tax gain or loss as a direct result of the merger. Additional details about the proposed merger are described in the enclosed Q&A and proxy statement/prospectus.

In the event that the merger described above is not approved, the Board of Trustees will determine what further action, if any, to take. In such event, Janus Henderson may recommend the liquidation of Janus Henderson International Opportunities Fund.

The proposal will be presented to shareholders at a special meeting of shareholders to be held on May 18, 2023. The proposal is briefly summarized in the synopsis that precedes the enclosed proxy statement/prospectus. The proxy statement/ prospectus includes a detailed discussion of the proposal, which you should read carefully.

The Board of Trustees of the Trust unanimously recommends that

shareholders vote FOR the proposal.

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You can vote in one of four ways:

Your vote is extremely important, so please read the enclosed proxy statement/prospectus carefully and submit your vote. If you have any questions about the proposal, please call our proxy solicitor, Computershare Fund Services, at 1-866-438-2987.

Thank you for your consideration of this important proposal. We value the trust and confidence you have placed with us and look forward to continuing our relationship with you.

Sincerely,

/s/ Michelle R. Rosenberg

Michelle R. Rosenberg

Chief Executive Officer and President

Janus Investment Fund

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JANUS INVESTMENT FUND

Janus Henderson International Opportunities Fund

151 Detroit Street

Denver, Colorado 80206

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

Notice is hereby given that the Board of Trustees of Janus Investment Fund (the “Trust”) has called a Special Meeting of Shareholders of Janus Henderson International Opportunities Fund (the “Target Fund”), a series of the Trust, to be held at the offices of Janus Henderson Investors, 151 Detroit Street, Denver, Colorado 80206, on May 18, 2023, at 10:00 a.m. Mountain Time (together with any adjournments or postponements thereof, the “Meeting”). At the Meeting, shareholders will be asked to vote on the proposal set forth below (the “Proposal”), and to transact such other business, if any, as may properly come before the Meeting.

Any shareholder who owned shares of the Target Fund as of the close of business on February 24, 2023 will receive notice of the Meeting and will be entitled to vote at the Meeting on the Proposal. The persons named as proxies will vote in their discretion on any other business that may properly come before the Meeting.

In the event that the necessary quorum to transact business or the vote required to approve the Proposal is not obtained at the Meeting, the chairperson of the Meeting may propose one or more postponements or adjournments to permit further solicitation of proxies. Any such postponement or adjournment will require the affirmative vote of the holders of a majority of shares of the Target Fund entitled to vote that are present in person or by proxy at the Meeting. If a quorum is not present, the persons named as proxies will vote the proxies, in accordance with applicable law, in favor of postponement or adjournment if they determine additional solicitation is warranted and in the interests of the Target Fund.

Shareholders are urged to take advantage of the Internet or telephonic voting procedures described on the enclosed proxy card(s), or complete, sign and date the enclosed proxy card(s) and return it in the enclosed addressed envelope, which needs no postage if mailed in the United States. If you wish to attend the Meeting and vote your shares in person at that time, you will still be able to do so.

The Board of Trustees unanimously recommends that shareholders vote FOR the Proposal.

By Order of the Board of Trustees,

/s/ Michelle R. Rosenberg

Michelle R. Rosenberg

Chief Executive Officer and President

Janus Investment Fund

March 8, 2023

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE SPECIAL MEETING OF SHAREHOLDERS TO BE HELD ON MAY 18, 2023:

The enclosed Proxy Statement/Prospectus is available free of charge at the website listed on your proxy card(s). The Funds’ most recent annual report and any more recent semiannual report are available free of charge at janushenderson.com/info

(or janushenderson.com/reports if you hold Class D Shares).

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INSTRUCTIONS FOR SIGNING PROXY CARD(S)

The following general rules for signing proxy card(s) may be of assistance to you and may avoid any delay involved in validating your vote if you fail to sign your proxy card(s) properly.

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PROXY STATEMENT/PROSPECTUS

March 8, 2023

Relating to the acquisition of the assets of

JANUS HENDERSON INTERNATIONAL OPPORTUNITIES FUND,

by and in exchange for shares of beneficial interest of

JANUS HENDERSON OVERSEAS FUND,

each a series of Janus Investment Fund

151 Detroit Street

Denver, Colorado 80206-4805

1-800-525-3713 (if you hold Class D Shares)

1-877-335-2687 (if you hold shares through a plan sponsor,

broker-dealer, or other intermediary)

INTRODUCTION

This proxy statement/prospectus (the “Proxy Statement/Prospectus”) is being furnished to shareholders of Janus Henderson International Opportunities Fund (the “Target Fund”), a series of Janus Investment Fund (the “Trust”), in connection with a special meeting of the Target Fund, to be held at the offices of Janus Henderson Investors, 151 Detroit Street, Denver, Colorado 80206, on May 18, 2023, at 10:00 a.m. Mountain Time (together with any adjournments or postponements thereof, the “Meeting”). The Board of Trustees of the Trust (the “Board of Trustees,” or the “Trustees”) is soliciting proxies from shareholders of the Target Fund for the Meeting.

At the Meeting, shareholders will be asked to vote on the proposal set forth below (the “Proposal”), and to transact such other business, if any, as may properly come before the Meeting.

Proposal 1.    Approve an Agreement and Plan of Reorganization, which provides for the transfer of all or substantially all of the assets of the Target Fund to Janus Henderson Overseas Fund (the “Acquiring Fund”) in exchange for shares of beneficial interest of the Acquiring Fund and the assumption by the Acquiring Fund of all of the liabilities of the Target Fund.

We sometimes refer to the Target Fund and the Acquiring Fund as the “Funds.” The Agreement and Plan of Reorganization for this proposed transaction is sometimes referred to herein as the “Plan,” and the transaction contemplated by the Plan sometimes are referred to herein as the “Merger.”

As a result of the proposed Merger, each shareholder of the Target Fund will receive a number of full and fractional shares of the Acquiring Fund equal in value to their holdings in the Target Fund as of the close of trading on the New York Stock Exchange (“NYSE”) on the closing date of the Merger. The number of shares you will receive in the Merger will be determined by the relative net asset value (“NAV”) of each class of shares of the Target Fund and the corresponding class of shares of the

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Acquiring Fund. Janus Henderson Investors US LLC (“Janus Henderson” or the “Adviser”) is the investment adviser for both the Target Fund and the Acquiring Fund and will remain the investment adviser of the Acquiring Fund following the completion of the Merger. After the Merger is completed, the Target Fund will be liquidated. The closing of the Merger is contingent upon approval of the Plan by shareholders of the Target Fund. A form of the Plan is attached as Appendix A. Assuming shareholder approval and the satisfaction or waiver of other closing conditions, the Merger is expected to occur on or about June 2, 2023, or as soon as practicable thereafter (the “Closing Date”).

This Proxy Statement/Prospectus, Notice of Special Meeting, and the proxy card(s) are first being mailed to shareholders of the Target Fund on or about March 23, 2023. Shareholders of record of the Target Fund as of the close of business on February 24, 2023 (the “Record Date”) are entitled to notice of and to vote at the Meeting.

The Board of Trustees unanimously recommends that shareholders vote FOR the Proposal.

This Proxy Statement/Prospectus, which you should read carefully and retain for future reference, sets forth the information that you should know about the Target Fund, the Acquiring Fund, and the Proposal, before voting on the Proposal. The Funds have similar investment objectives, investment policies, and principal investment strategies, including that both Funds are classified as “diversified.” Each Fund pursues its investment objective by primarily investing in securities of companies outside of the United States. The Adviser believes that the Target Fund’s shareholders may benefit from being shareholders of one larger combined international equity fund, creating the potential for broader asset growth and a more stable asset base, while realizing portfolio management and operational efficiencies. Additionally, Janus Henderson believes that Target Fund shareholders may benefit from the centralized research approach employed by the Acquiring Fund, which differs from the multi-sub-portfolio approach employed by the Target Fund wherein underlying sleeve sub-portfolio managers focus on their highest conviction ideas. After considering the Adviser’s recommendation and other factors, the Board of Trustees has approved the Proposal and unanimously recommends that shareholders vote FOR the Proposal.

The Proxy Statement/Prospectus serves as a prospectus of the Acquiring Fund in connection with the issuance of Acquiring Fund common shares in the Merger. No person has been authorized to give any information or make any representation not contained in this Proxy Statement/Prospectus and, if so given or made, such information or representation must not be relied upon as having been authorized. This Proxy Statement/Prospectus does not constitute an offer to sell or a solicitation of an offer to buy any securities in any jurisdiction in which, or to any person to whom, it is unlawful to make such offer or solicitation.

Shares of the Acquiring Fund have not been approved or disapproved by the U.S. Securities and Exchange Commission (“SEC”) nor has the SEC passed upon the accuracy or adequacy of this Proxy Statement/Prospectus. Any representation to the contrary is a criminal offense.

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Incorporation by Reference

For more information about the investment objective, strategies, restrictions, and risks of the Funds, see:

The above documents have been filed with the SEC and are incorporated by reference herein as appropriate. The prospectus of the applicable class of shares of each Fund and its annual report have previously been delivered to the respective Fund’s shareholders.

You can obtain free copies of any of the foregoing Fund documents by contacting your plan sponsor, broker-dealer, or financial intermediary, or by contacting a Janus Henderson representative at 1-877-335-2687 (or 1-800-525-3713 if you hold Class D Shares). The reports are also available, without charge, at janushenderson.com/info (or janushenderson.com/reports if you hold Class D Shares), or by sending a written request to the Secretary of the Trust at 151 Detroit Street, Denver, Colorado 80206-4805.

A Statement of Additional Information dated March 8, 2023 relating to the Merger has been filed with the SEC and is incorporated by reference into this Proxy Statement/Prospectus. You can obtain a free copy of that document by contacting your plan sponsor, broker-dealer, or financial intermediary or by contacting a Janus Henderson representative at 1-877-335-2687 (or 1-800-525-3713 if you hold Class D Shares).

The shares of the Funds are not deposits or obligations of, or guaranteed or endorsed by, any financial institution or the U.S. Government, are not insured by the Federal Deposit Insurance Corporation, the Federal Reserve Board or any other government agency, and involve risk, including the possible loss of the principal amount invested.

Each Fund is subject to the informational requirements of the Securities Exchange Act of 1934, as amended, and the Investment Company Act of 1940, as

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amended (the “1940 Act”), and, in accordance therewith, files reports, proxy materials, and other information with the SEC. You may obtain reports and other information about the Funds from the Electronic Data Gathering Analysis and Retrieval (EDGAR) Database on the SEC’s website at http://www.sec.gov, or by sending an electronic request by email to publicinfo@sec.gov, followed by paying a duplicating fee.

The following chart outlines the share classes of the Funds involved in the Merger and their respective ticker symbols:

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PROXY STATEMENT/PROSPECTUS

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Q&A / SYNOPSIS

The following synopsis provides a brief overview of the matter to be voted on at the Meeting, including information typically of concern to shareholders considering a proposed combination of mutual funds. The Proxy Statement/Prospectus contains more detailed information about the Proposal, and we encourage you to read it in its entirety before voting. This synopsis is qualified in its entirety by the remainder of this Proxy Statement/Prospectus. The description of the Plan is qualified by reference to the full text of the form of the Plan, which is attached as Appendix A to this Proxy Statement/Prospectus.

Proposal 1: Approval of the Plan

Janus Henderson believes that the Target Fund’s shareholders may benefit from being shareholders of one larger combined international equity fund, creating the potential for broader asset growth and a more stable asset base while realizing portfolio management and operational efficiencies. Additionally, Janus Henderson believes that Target Fund shareholders may benefit from the centralized research approach employed by the Acquiring Fund, which differs from the multi-sub-portfolio approach employed by the Target Fund, wherein underlying sleeve sub-portfolio managers focus on their highest conviction ideas. Janus Henderson is also seeking to streamline its international equity offerings for better positioning within the marketplace.

The Board of Trustees has approved a proposal to combine the Funds by having the Target Fund transfer all or substantially all of its assets to the Acquiring Fund in exchange for shares of beneficial interest of the Acquiring Fund and the assumption by the Acquiring Fund of all of the liabilities of the Target Fund. The shares of the Acquiring Fund received by the Target Fund will be distributed pro rata to Target Fund shareholders of record, determined as of the close of business on the Closing Date. After the Merger is completed, the Target Fund will be liquidated.

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The Board of Trustees unanimously recommends that shareholders of the Target Fund vote FOR the Plan.

Further information regarding the factors considered by the Board of Trustees in making its recommendation is included below in the section of this Proxy Statement/Prospectus titled “THE MERGER,” under the sub-caption “Reasons for the Merger.”

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Similarities:

Investment Personnel:    George Maris serves as lead portfolio manager for both the Target Fund and the Acquiring Fund, and is expected to continue to serve in such capacity for the Acquiring Fund following the Merger.

Investment Objectives:

Principal Investment Strategies:

Diversification:    Each Fund is classified as “diversified” under the 1940 Act, meaning that each Fund may not, with respect to 75% of its total assets, invest more than 5% of its total assets in any issuer and may not own more than 10% of the outstanding voting securities of an issuer.

Benchmark:    Each Fund’s benchmark index is the MSCI All Country World ex-USA Index^SM.

Differences:

Investment Personnel and Approach:    Each Fund has a different investment team, with one common portfolio manager. The Target Fund is co-managed by George Maris and Paul O’Connor, with Mr. Maris serving as lead portfolio manager, utilizing sleeve portfolio managers that focus on their highest conviction ideas. The Acquiring Fund is co-managed by George Maris and Julian

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McManus, with Mr. Maris serving as lead portfolio manager, utilizing a centralized research approach. The Acquiring Fund’s portfolio managers will continue to manage the Fund after the Merger.

Principal Investment Strategies:

Further information comparing the Funds’ investment objective, strategies, restrictions, and risks is included below under “Summary of the Funds” and in Appendix B of this Proxy Statement/Prospectus.

The Target Fund pays a contractual investment advisory fee to the Adviser at a fixed rate based on the Fund’s average daily net assets, as set forth below:

For the fiscal year ended September 30, 2022, the Target Fund paid an investment advisory fee to the Adviser at the annual rate of 1.00% on a gross basis and 0.74% after fee waivers. No portion of the Target Fund’s investment advisory fee is based on performance.

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The Acquiring Fund’s base investment advisory fee rate paid to the Adviser, prior to any performance adjustment, is an annual rate of 0.64% of the Fund’s average daily net assets (the “Base Fee Rate”). The Base Fee Rate adjusts up or down by a variable of up to 0.15% (assuming constant assets) on a monthly basis based upon the Acquiring Fund’s performance relative to its benchmark index, the MSCI All Country World ex-USA Index^SM, during a performance measurement period, which is the 36-month period preceding the end of the month for which the fee is calculated (the “Performance Adjustment”). For purposes of computing the Base Fee Rate and the Performance Adjustment, net assets are averaged over different periods (average daily net assets during the previous month for the Base Fee Rate, versus average daily net assets during the performance measurement period for the Performance Adjustment). For the fiscal year ended September 30, 2022, the Acquiring Fund paid an investment advisory fee (including the Performance Adjustment) to the Adviser at the annual rate of 0.76% of the Acquiring Fund’s average daily net assets due to the Acquiring Fund’s outperformance relative to the MSCI All Country World ex-USA Index^SM over a rolling 36-month performance measurement period.

In addition, the Adviser has agreed to waive its investment advisory fee and/or reimburse certain other Fund operating expenses to the extent that total annual operating expenses exceed 0.83% for the Target Fund, and 0.82% for the Acquiring Fund (excluding any performance adjustments to management fees, the fees payable pursuant to a Rule 12b-1 plan, shareholder servicing fees, such as transfer agency fees (including out-of-pocket costs), administrative services fees and any networking/omnibus fees payable by any share class, brokerage commissions, interest, dividends, taxes, acquired fund fees and expenses, and extraordinary expenses). The contractual waiver is in effect for at least a one-year period commencing on January 27, 2023 for the Target Fund, and through at least March 31, 2024 for the Acquiring Fund. For at least a one-year period commencing on January 27, 2023, the Adviser has also agreed to reduce the administrative services fee payable by the Target Fund’s Class R Shares pursuant to the Fund’s Transfer Agency Agreement so that such fees do not exceed 0.21% of Class R Shares’ average daily net assets. Transfer agency fees are not waived for Class R Shares of the Acquiring Fund.

Pro forma fee, expense, and financial information is included in this Proxy Statement/Prospectus.

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Additional pro forma fee, expense, and financial information is included in this Proxy Statement/Prospectus.

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If the Merger is approved, it is expected that approximately 75% of the portfolio holdings of the Target Fund will be sold by the Acquiring Fund after the closing of the Merger. The Adviser anticipates that any sales of securities to align the portfolio holdings of the Target Fund with those of the Acquiring Fund following the Merger will result in a net capital loss to the Acquiring Fund. Accordingly, the Adviser does not anticipate that the Merger will result in adverse tax consequences to shareholders of either of the Funds (as shareholders of the Acquiring Fund following the completion of the Merger). If, however, due to market conditions or other factors, the Acquiring Fund experiences a net capital gain in connection with the disposition of securities following the Merger, shareholders of either of the Funds (as shareholders of the Acquiring Fund following the completion of the Merger) will be taxed on any resulting capital gain distributions. Additional information about the repositioning of the Target Fund’s portfolio in connection with the Merger can be found under “Will either Fund pay direct fees or expenses associated with the Merger?” below.

Janus Henderson currently serves as investment adviser to both Funds and will continue as the investment adviser to the Acquiring Fund following the completion of the Merger. The administrator, custodian, transfer agent, auditor, and distributor are the same for the Funds and will not change as a result of the Merger.

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Voting Information

A quorum of shareholders is required to take action at the Meeting. The presence in person or by proxy of the holders of record of 30% of the shares outstanding and entitled to vote at the Meeting constitutes a quorum.

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Whichever method you choose, please take the time to read the full text of this Proxy Statement/Prospectus before you vote.

It is important that shareholders respond to ensure that there is a quorum for the Meeting. If we do not receive your response within a few weeks, you may be contacted by Computershare Fund Services (“Computershare”), the proxy solicitor engaged by Janus Henderson, who will remind you to vote your shares and help you return your proxy. If a quorum is not present or sufficient votes to approve the Proposal are not received by the date of the Meeting, the chairperson of the Meeting may adjourn the Meeting to a later date so that we can continue to seek additional votes.

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PROPOSAL 1 – THE MERGER OF JANUS HENDERSON INTERNATIONAL OPPORTUNITIES FUND INTO JANUS HENDERSON OVERSEAS FUND

SUMMARY

This section provides a summary of certain information with respect to the Merger, the Target Fund, and the Acquiring Fund, including but not limited to, comparative information regarding each Fund’s investment objective, fees and expenses, principal investment strategies and risks, historical performance, and other information. Please note that this is only a brief discussion and is qualified in its entirety by reference to the complete information contained herein, including the Funds’ prospectuses which are incorporated by reference.

There is no assurance that a Fund will achieve its stated objective. Each Fund is designed for long-term investors seeking an international equity portfolio.

Comparison of Investment Advisory Fee Rates

As of September 30, 2022, the Target Fund investment advisory fee rate was 1.00%, excluding waivers, as compared to the rate of 0.76% for the Acquiring Fund at that same date. However, because the Target Fund’s investment advisory fee rate schedule includes breakpoints as assets grow, if the Acquiring Fund’s assets under management grew following the Merger, and exceed approximately $7.0 billion (which could happen if the Acquiring Fund’s recent growth continues), the Acquiring Fund’s advisory fee, including the Base Fee Rate and maximum Performance Adjustment, of 0.79% would exceed the breakpoint fee rates for the Target Fund at similar asset levels. This would result in the shareholders of the Target Fund paying a higher investment advisory fee rate as Acquiring Fund shareholders than they would otherwise pay if remaining a Target Fund shareholder and the Target Fund also grew to $7 billion in assets (roughly ten times its size as of September 30, 2022). Note that this analysis excludes the impact of any investment advisory fee waivers currently in place for the Target Fund. Refer to the “Other Comparative Information about the Funds – Management Expenses” section in this Proxy Statement/Prospectus for additional information with further description in the Fund’s Statement of Additional Information, as supplemented (“SAI”), which is incorporated by reference herein.

Current and Pro Forma Fees and Expenses

The following tables compare the fees and expenses you may bear directly or indirectly as an investor in the Target Fund or the Acquiring Fund versus the estimated (“pro forma”) fees and expenses of the Acquiring Fund, assuming consummation of the Merger as of the first day of the fiscal year ended September 30, 2022. Fees and expenses shown for the Target Fund and the Acquiring Fund were determined based on each Fund’s average daily net assets for the fiscal year ended September 30, 2022. Total net assets as of September 30, 2022 were approximately $647 million for the Target Fund, approximately $1.671 billion for the Acquiring Fund, and approximately $2.318 billion for the Acquiring Fund on a pro forma basis assuming the Merger closed as of the fiscal year ended September 30, 2022.

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The pro forma fees and expenses are estimated in good faith and are hypothetical, and do not reflect any change in expense ratios resulting from a change in assets under management since September 30, 2022. More current total net asset information for the Target Fund is available at janushenderson.com/en-us/advisor/product/internationalopportunities-fund (or janushenderson.com/en-us/investor/product/international-opportunities-fund if you hold Class D Shares) and for the Acquiring Fund at janushenderson.com/en-us/advisor/product/overseas-fund (or janushenderson.com/en-us/investor/product/overseas-fund if you hold Class D Shares). It is important for you to know that a decline in a Fund’s average daily net assets during the current fiscal year and after the Merger, as a result of redemptions from the Fund in excess of subscriptions or declines in net asset value per share resulting from market volatility or other factors, could cause the Fund’s expense ratio to be higher than the fees and expenses shown, which means you could pay more if you buy or hold shares of the Funds.

Annual Fund Operating Expenses

Annual Fund Operating Expenses are paid out of a Fund’s assets and include fees for portfolio management, administration and administrative services, including recordkeeping, accounting or sub-accounting, and other shareholder services. You do not pay these fees directly, but as the examples in the tables below show, these costs are borne indirectly by all shareholders.

All Fund expenses 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.

Other Expenses for Class S Shares, Class R Shares, and Class T Shares include an administrative services fee of up to 0.25% of the average daily net assets of each class to compensate Janus Henderson Services, the Funds’ transfer agent, for providing, or arranging for the provision by intermediaries of, administrative services, including recordkeeping, sub-accounting, order processing for omnibus or networked accounts, or other shareholder services provided on behalf of retirement plan participants, pension plan participants, or other underlying investors investing through institutional channels. Other Expenses for Class D Shares include an administrative services fee based on the average daily net assets of Class D Shares for shareholder services provided by Janus Henderson Services, as detailed below:

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Other Expenses for all classes of the Funds may include reimbursement to the Adviser of its out-of-pocket costs for services as administrator and reimbursement to Janus Henderson Services of its out-of-pocket costs for serving as transfer agent and providing, or arranging by others the provision of, servicing to shareholders.

The Annual Fund Operating Expenses shown in the table below represent annualized expenses for the Target Fund and the Acquiring Fund, as well as those estimated for the Acquiring Fund on a pro forma basis, assuming consummation of the Merger as of the first day of the fiscal year ended September 30, 2022.

Changes to asset levels of the Target Fund or the expenses and asset levels of the Acquiring Fund between the date of this Proxy Statement/Prospectus and the anticipated Closing Date for the Merger could impact the expenses shown below that will be paid by the Acquiring Fund.

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Examples:

The Examples are intended to help you compare the cost of investing in the Target Fund, the Acquiring Fund, and the Acquiring Fund after the Merger with the cost of investing in other mutual funds. The Examples assume that you invest $10,000 for the time periods indicated and reinvest all dividends and distributions. The Examples also assume that your investment has a 5% return each year and that the Funds’ operating expenses are equal to the Total Annual Fund Operating Expenses After Fee Waiver for the first year, as applicable, and the Total Annual Fund Operating Expenses thereafter. Class C Shares automatically convert to Class A Shares after eight years. The Example for Class C Shares for the ten-year period reflects the conversion to Class A Shares. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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Portfolio Turnover

Each 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 Examples, affect each Fund’s performance. During the most recent fiscal year, the Target Fund’s portfolio turnover rate was 88% of the average value of its portfolio and the Acquiring Fund’s portfolio turnover rate was 32% of the average value of its portfolio. During the current fiscal period, it is anticipated that the Acquiring Fund’s portfolio turnover will be higher due to repositioning of the combined portfolio following the completion of the Merger.

After the Merger is completed, the portfolio managers of the Acquiring Fund may, in their discretion, sell securities acquired from the Target Fund. To the extent that the portfolio managers choose to sell a significant percentage of such securities, the Acquiring Fund’s brokerage costs may be higher than they otherwise would have been. Such transactions would be intended to better align the combined post-Merger portfolio with the pre-Merger portfolio of the Acquiring Fund. If the Merger is approved, it is expected that approximately 75% of the portfolio holdings of the Target Fund will be sold by the Acquiring Fund after the closing of the Merger. Brokerage commissions or other transaction costs are estimated to be approximately $1.3 million (0.042% of the pro forma combined net assets of the Target Fund and the Acquiring Fund as of January 18, 2023). The actual brokerage commissions or other transaction costs will vary depending upon market conditions, shareholder activity, the Target Fund’s portfolio holdings at the time of the Merger, and the specific securities transferred to the Acquiring Fund. The Adviser anticipates that any sales of securities to align the portfolio holdings of the Target Fund with those of the Acquiring Fund following the Merger will result in a net capital loss to the Acquiring Fund. Accordingly, the Adviser does not anticipate that the Merger will result in adverse tax consequences to shareholders of either of the Funds (as shareholders of the Acquiring Fund following the completion of the Merger). If, however, due to market conditions or other factors, the Acquiring Fund experiences a net capital gain in connection with the disposition of securities following the Merger, shareholders of either of the Funds (as shareholders of the Acquiring Fund following the completion of the Merger) normally would be taxed on any resulting capital gain distributions.

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Investment Objectives

The Target Fund seeks long-term capital appreciation primarily through investment in equities of non-U.S. companies. The Acquiring Fund seeks long-term growth of capital.

Principal Investment Strategies

The Funds have substantially similar investment policies and principal investment strategies, including that both Funds are classified as “diversified,” and primarily invest in securities outside of the United States. As “diversified” Funds, each Fund may not, with respect to 75% of its total assets, invest more than 5% of its total assets in any issuer and may not own more than 10% of the outstanding voting securities of an issuer.

The following is intended to compare the Funds’ principal investment strategies. The Acquiring Fund will continue to have the same investment strategies shown below following the Merger. This information is qualified in its entirety by the prospectuses of each Fund, which are incorporated by reference.

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For additional information on the Funds’ principal investment strategies and related risks, please refer to the “Additional Information About the Funds” section of this Proxy Statement/Prospectus and in Appendix B.

Fundamental Investment Policies and Restrictions

The fundamental investment policies and restrictions for the Funds are identical, with the exception of the Funds’ fundamental policy on borrowing. The following is intended to compare the Funds’ fundamental investment policies and restrictions. The Acquiring Fund will continue to have the same fundamental investment policies and restrictions below following the Merger.

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Principal Investment Risks

A Fund’s returns and yields will vary, and you could lose money. Each Fund is designed for long-term investors seeking an international equity portfolio, including common stocks. Common stocks tend to be more volatile than many other investment choices. The following is a summary of the principal risks associated with an investment in each Fund. Because the Funds have substantially similar investment objectives, investment policies, and principal investment strategies, the principal risks are also substantially similar for each Fund. Differences in risks between the Funds are noted below (an “X” indicates that the particular risk factor is included among a Fund’s principal investment risks disclosed in its prospectus.). Additional information about these risks is included below and described in greater detail later in this Proxy Statement/Prospectus under “Additional Information About the Funds – Additional Risks of the Funds.” As with any security, an investment in either Fund involves certain risks, including loss of principal. The fact that a particular risk is not identified does not mean that a Fund, as part of its overall investment strategy, does not invest or is precluded from investing in securities that give rise to that risk. This information is qualified in its entirety by the prospectuses of each Fund, which are incorporated by reference.

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Currency Risk.    Currency risk is the risk that changes in the exchange rate between currencies will adversely affect the value (in U.S. dollar terms) of an investment. 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.

Depositary Receipts Risk.    Depositary receipts are generally subject to the same sort of risks as direct investments in a foreign country, such as currency risk, market risk, and foreign exposure risk, because their values depend on the performance of a foreign security denominated in its home currency.

Derivatives Risk.    Derivatives can be volatile and involve risks in addition to the risks of the underlying referenced securities or asset. 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 entail the risk that the counterparty will default on its payment obligations. Derivatives used for hedging purposes may reduce or eliminate gains or cause losses if the market moves in a manner different from that anticipated by the portfolio managers or if the cost of the derivative outweighs the benefit of the hedge.

Emerging Markets Risk.    Each Fund invests in emerging market securities. Emerging markets securities involve a number of risks, which may result from less government supervision and regulation of business and industry practices (including the potential lack of strict finance and accounting controls and standards), stock exchanges, brokers, and listed companies. Information about emerging market companies, including financial information, may be less available or reliable and the Adviser’s ability to conduct due diligence with respect to such companies may be limited. Accordingly, these investments may be potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a current or future economic

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or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Funds’ investments. In addition, the taxation systems at the federal, regional, and local levels in developing or emerging market countries may be less transparent, inconsistently enforced, and subject to change. Emerging markets may be subject to a higher degree of corruption and fraud than developed markets and financial institutions and transaction counterparties may have less financial sophistication, creditworthiness, and/or resources than participants in developed markets. In addition, each Fund’s investments may be denominated in foreign currencies and therefore, changes in the value of a country’s currency compared to the U.S. dollar may affect the value of the Funds’ investments. To the extent that either Fund invests a significant portion of its assets in the securities of emerging markets issuers in or companies of a single country or region, it is more likely to be impacted by events or conditions affecting that country or region, which could have a negative impact on the Fund’s performance. Additionally, foreign and emerging market risks, including but not limited to price controls, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, nationalization, and restrictions on repatriation of assets may be heightened to the extent the Funds invest in Chinese local market securities. Foreign and emerging market risks may also be heightened to the extent the Funds have exposure to Chinese issuers through variable interest entities, which subjects the Funds to the risks associated with the underlying Chinese issuer or operating company.

ESG Integration Risk.    Certain sleeve portfolio managers of the Target Fund integrate ESG factors by incorporating ESG information into the Target Fund’s investment process. As a result, the Target Fund may have different exposures 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 Target 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 certain sleeve portfolio managers of the Target Fund may rely, continues to develop, and may be incomplete, inaccurate, use different methodologies or be applied differently across issuers and industries. Further, the regulatory landscape regarding ESG investing in the United States is still developing and future rules and regulations may require the Target Fund to modify or alter its investment policies.

Foreign Exposure Risk.    Each Fund may have exposure to foreign markets, including emerging markets, which can be more volatile than the U.S. market. As a result, the Fund’s returns and net asset value may be affected by fluctuations in currency exchange rates or political or economic conditions in a particular country. In some foreign markets, there may not be protection against failure by other parties to

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complete transactions. It may not be possible for the Fund to repatriate capital, dividends, interest, and other income from a particular country or governmental entity. In addition, a market swing in one or more countries or regions where the Fund has invested a significant amount of its assets may have a greater effect on the Fund’s performance than it would in a more geographically diversified portfolio. The Fund’s investments in emerging market countries, if any, may involve risks greater than, or in addition to, the risks of investing in more developed countries.

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

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 portfolio managers’ perception of a company’s growth potential is not realized, the securities purchased may not perform as expected, reducing a 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.

Industry and Sector Risk.    Although the Acquiring Fund does not concentrate its investments in specific industries or sectors, it may have a significant portion of its assets invested in securities of companies conducting similar business, or business within the same economic sector. Companies in the same industry or economic sector may be similarly affected by economic or market events, making the Fund more vulnerable to unfavorable developments than funds that invest more broadly. As the Fund’s portfolio becomes more concentrated, the Fund is less able to spread risk and

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potentially reduce the risk of loss and volatility. In addition, the Fund may be overweight or underweight in certain industries or sectors relative to its benchmark index, which may cause the Fund’s performance to be more or less sensitive to developments affecting those sectors.

Initial Public Offering Risk.    The Target Fund’s purchase of shares issued in an initial public offering (“IPO”) exposes it to the risks associated with companies that have little operating history as public companies, as well as to the risks inherent in those sectors of the market where these new issuers operate. Although IPO investments may have had a positive impact on the Target Fund’s performance in the past, there can be no assurance that the Fund will identify favorable IPO investment opportunities in the future. In addition, as the Fund increases in size, the impact of IPOs on the Fund’s performance will generally decrease.

Issuer Concentration Risk.    The Acquiring Fund’s portfolio may be comprised of a relatively small number of issuers in comparison to other funds. As a result, the Fund may be subject to greater risks than a fund that invests in a greater number of issuers. A change in the value of any single investment held by the Fund may affect the overall value of the Fund more than it would affect a fund that holds more investments. In particular, the Fund may be more susceptible to adverse developments affecting any single issuer held by the Fund and may be susceptible to greater losses because of these developments.

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

Market Risk.    The value of each Fund’s portfolio may decrease short-term market movements and over more prolonged market downturns. As a result, each Fund’s net asset value may fluctuate and it may be more difficult to value or sell the Fund’s holdings. Market risk may affect a single issuer, industry, economic sector, or the market as a whole. Market risk may be magnified if certain social, political, economic, and other conditions and events (such as terrorism, conflicts, including related sanctions, social unrest, natural disasters, epidemics and pandemics, including COVID-19) adversely interrupt the global economy and financial markets. It is

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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.

Portfolio Management Risk.    Each Fund is an actively managed investment portfolio and is therefore subject to the risk that the investment strategies employed for each Fund may fail to produce the intended results. Each Fund may underperform its benchmark index or other mutual funds with similar investment objectives.

REIT Risk.    REITs are subject to certain risks inherent in the direct ownership of real estate, including without limitation, a possible lack of mortgage funds and associated interest rate risks, overbuilding, property vacancies, increases in property taxes and operating expenses, changes in zoning laws, losses due to environmental damages and changes in neighborhood values and appeal to purchasers. In addition, a REIT could fail to qualify for tax-free pass-through of its income under the Internal Revenue Code of 1986, as amended, 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 Acquiring Fund. Dividends received by the Acquiring Fund from a REIT generally will not constitute qualified dividend income.

Securities Lending Risk.    There is the risk that when portfolio securities are lent, the securities may not be returned on a timely basis, and the Acquiring 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.

Small- and Mid-Sized Companies Risk.    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. For example, while small- and mid-sized companies may realize more substantial growth than larger or more established issuers, they may also suffer more significant losses as a result of their narrow product lines, limited operating history, greater exposure to competitive threats, limited financial resources, limited trading markets, and the potential lack of management depth. 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 or more established companies. These holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on each Fund’s returns, especially as market conditions change.

Value Investing Risk.    Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, “value” stocks may perform

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differently than other types of stocks and from the market as a whole, and can continue to be undervalued by the market for long periods of time. It is also possible that a value stock will never appreciate to the extent expected by the portfolio managers.

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

Comparison of Fund Performance

The following information provides some indication of the risks of investing in each Fund by showing how each Fund’s performance has varied over time. The Acquiring Fund, upon the completion of the Merger, will maintain the accounting history and performance track record of the Acquiring Fund.

Acquiring Fund:

The following information provides some indication of the risks of investing in the Acquiring Fund by showing how the Fund’s performance has varied over time. Class T Shares (formerly named Class J Shares, the initial share class) of the Acquiring Fund commenced operations with the Fund’s inception. Class A Shares, Class C Shares, Class S Shares, Class I Shares, and Class R Shares of the Acquiring Fund commenced operations on July 6, 2009. Class N Shares of the Acquiring Fund commenced operations on May 31, 2012.

If Class A Shares, Class C Shares, Class S Shares, Class I Shares, and Class R Shares of the Acquiring Fund had been available during periods prior to July 6, 2009, or Class N Shares of the Acquiring Fund had been available during periods prior to May 31, 2012, the performance shown for each respective share class may have been

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different. The performance shown for the periods following the Acquiring Fund’s commencement of Class A Shares, Class C Shares, Class S Shares, Class I Shares, Class N Shares, and Class R Shares reflects the fees and expenses of each respective share class, net of any applicable fee and expense limitations or waivers.

The bar chart depicts the change in performance from year to year during the periods indicated. The bar chart figures do not include any applicable sales charges that an investor may pay when they buy or sell Class A Shares or Class C Shares of the Acquiring Fund. If sales charges were included, the returns would be lower. The table compares the Acquiring Fund’s average annual returns for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Acquiring Fund’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

The Acquiring Fund’s past performance (before and after taxes) does not necessarily indicate how it will perform in the future. Updated performance information is available at janushenderson.com/performance or by calling 1-877-335-2687.

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The following information provides some indication of the risks of investing in the Acquiring Fund by showing how the Fund’s performance has varied over time. Class D Shares of the Acquiring Fund commenced operations on February 16, 2010, as a result of the restructuring of Class J Shares, the predecessor share class. The performance shown for Class D Shares for periods prior to February 16, 2010, reflects the performance of the Acquiring Fund’s former Class J Shares, calculated using the fees and expenses in effect during the periods shown, net of any applicable fee and expense limitations or waivers. If Class D Shares of the Acquiring Fund had been available during periods prior to February 16, 2010, the performance shown may have been different. The performance shown for the periods following the Acquiring Fund’s commencement of Class D Shares reflects the fees and expenses of Class D Shares, net of any applicable fee and expense limitations or waivers.

The bar chart depicts the change in performance from year to year during the periods indicated. The table compares the Acquiring Fund’s average annual returns for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Acquiring Fund’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

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

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The Acquiring Fund’s primary benchmark index is the MSCI All Country World ex-USA Index. The MSCI All Country World ex-USA Index is used to calculate the Fund’s performance fee adjustment. The index is described below.

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

After-tax returns are only shown for Class T Shares of the Acquiring Fund. After-tax returns for the other classes of Shares will vary from those shown for Class T Shares due to varying sales charges (as applicable), fees, and expenses among the classes.

After-tax returns are calculated using distributions for the Acquiring Fund’s Class D Shares for the periods following February 16, 2010; and for the Acquiring Fund’s Class J Shares, the predecessor share class, for periods prior to February 16, 2010. If Class D Shares of the Acquiring Fund had been available during these earlier periods, distributions may have been different and thus, after-tax returns may have been different from those shown. After-tax returns are calculated using the historically highest individual federal marginal income tax rates and do not reflect the

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

Target Fund:

The following information provides some indication of the risks of investing in the Target Fund by showing how the Fund’s performance has varied over time. Returns shown for periods prior to June 5, 2017, are those of the Predecessor Fund, Henderson International Opportunities Fund (the “Predecessor Fund”). The Predecessor Fund was advised by Henderson Global Investors (North America) Inc. and subadvised by Henderson Investment Management Limited. Class A Shares, Class C Shares, Class R Shares, Class I Shares, Class IF Shares, and Class R6 Shares of the Predecessor Fund were reorganized into Class A Shares, Class C Shares, Class R Shares, Class I Shares (Class I Shares and Class IF Shares of the Predecessor Fund were reorganized into Class I Shares of the Fund), and Class N Shares, respectively, of the Target Fund on June 2, 2017. Class A Shares and Class C Shares of the Predecessor Fund commenced operations with the Predecessor Fund’s inception on August 31, 2001. Class R Shares, Class I Shares, Class R6 Shares, and Class IF Shares of the Predecessor Fund commenced operations on September 30, 2005, March 31, 2009, November 30, 2015, and March 31, 2016, respectively. Class S Shares and Class T Shares of the Target Fund commenced operations on June 5, 2017.

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Returns of the Target Fund will be different from the Predecessor Fund as they have different expenses.

The bar chart depicts the change in performance from year to year during the periods indicated. The bar chart figures do not include any applicable sales charges that an investor may pay when they buy or sell Class A Shares or Class C Shares of the Target Fund. If sales charges were included, the returns would be lower. The table compares the Target Fund’s average annual returns for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Target Fund’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

The Target Fund’s (and the Predecessor Fund’s) past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available at janushenderson.com/performance or by calling1-877-335-2687.

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The following information provides some indication of the risks of investing in the Target Fund by showing how the Fund’s performance has varied over time. Class D Shares of the Fund commenced operations on June 5, 2017. The performance shown for Class D Shares for periods prior to June 5, 2017, reflects the performance of Class A Shares of the Predecessor Fund, calculated using the fees and expenses of Class A Shares of the Predecessor Fund (without sales charges), net of any applicable fee and expense limitations or waivers. The Predecessor Fund was advised by Henderson Global Investors (North America) Inc. and subadvised by Henderson Investment Management Limited. Class A Shares, Class C Shares, Class R Shares, Class I Shares, Class IF Shares, and Class R6 Shares of the Predecessor Fund were reorganized into Class A Shares, Class C Shares, Class R Shares, Class I Shares (Class I Shares and Class IF Shares of the Predecessor Fund were reorganized into Class I Shares of the Fund), and Class N Shares, respectively, of the Fund on June 2, 2017. In connection with this reorganization, certain shareholders of the Predecessor Fund who held shares directly with the Predecessor Fund and not through an intermediary had the Class A Shares, Class C Shares, Class R Shares, Class I Shares, and Class N Shares of the Fund received in the merger automatically exchanged for Class D Shares

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of the Fund following the merger. If Class D Shares of the Fund had been available during periods prior to June 5, 2017, the performance shown may have been different because the Fund and the Predecessor Fund have different expenses. The performance shown for the periods following the Fund’s commencement of Class D Shares reflects the fees and expenses of Class D Shares, net of any applicable fee and expense limitations or waivers.

The bar chart depicts the change in performance from year to year during the periods indicated. The table compares the Fund’s average annual returns for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Fund’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

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

Average Annual Total Returns (periods ended 12/31/22)

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The Target Fund’s primary benchmark index is the MSCI All Country World ex-USA Index. The index is described below.

After-tax returns are calculated using distributions for the Predecessor Fund’s Class A Shares for the period prior to June 5, 2017. If Class A Shares of the Target Fund had been available during periods prior to June 5, 2017, the distributions used to calculate the after-tax returns may have been different. After-tax returns are calculated using the historically highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on your individual tax situation and may differ from those shown in the preceding table. The after-tax return information shown above does not apply to Fund shares held through a tax-advantaged account, such as a 401(k) plan or an IRA.

After-tax returns are only shown for Class A Shares of the Fund. After-tax returns for the other classes of Shares will vary from those shown for Class A Shares due to varying sales charges (as applicable), fees, and expenses among the classes.

After-tax returns are calculated using distributions for the Predecessor Fund’s Class A Shares for the period prior to June 5, 2017. If Class D Shares of the Fund had been available during periods prior to June 5, 2017, the distributions used to calculate the after-tax returns may have been different. After-tax returns are calculated using the historically highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on your individual tax situation and may differ from those shown in the preceding table. The after-tax return information shown above does not apply to Fund shares held through a tax-advantaged account, such as a 401(k) plan or an IRA.

Management of the Funds

Investment Adviser:    Janus Henderson is the investment adviser for the Acquiring Fund and the Target Fund and will remain the investment adviser of the Acquiring Fund after the Merger.

Portfolio Management:    The Acquiring Fund’s investment personnel will continue to manage the Acquiring Fund after the Merger. For more information about each Fund’s investment personnel, please refer to “Other Comparative Information about the Funds – Investment Personnel.”

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Purchase and Sale of Fund Shares

Minimum Investment Requirements