The advisor will waive a portion of the fund's management fee equal to the expenses attributable to the management fees of American Century-advised underlying funds. The amount of this waiver will fluctuate depending on the fund's daily allocations to such funds. This waiver is expected to remain in effect permanently, and it cannot be terminated without the approval of the Board of Trustees.

Exchange Traded Funds (ETFs) are bought and sold through exchange trading at market price (not NAV), and are not individually redeemed from the fund. Shares may trade at a premium or discount to their NAV in the secondary market. Brokerage commissions will reduce returns.

The fund's performance and risks reflect the performance and risks of the underlying funds in which it invests. By investing in underlying funds, the primary fund becomes a shareholder of the underlying fund and bears its proportionate share of the underlying fees and expenses.

This fund is an actively managed ETF that does not seek to replicate the performance of a specified index. To determine whether to buy or sell a security, the portfolio managers consider, among other things, various fund requirements and standards, along with economic conditions, alternative investments, interest rates and various credit metrics. If the portfolio manager considerations are inaccurate or misapplied, the fund's performance may suffer.

The fund's performance and risks reflect the performance and risks of the underlying funds in which it invests. The advisor will waive a portion of the fund's management fee equal to the expenses attributable to the management fees of American Century-advised underlying funds. However, shareholders will indirectly bear some other fees and expenses of underlying funds, thereby absorbing duplicative levels of fees with respect to investments in the underlying funds. An increase in fees and expenses of an underlying fund or a reallocation of the fund's investments to underlying funds with higher fees or expenses will increase the fund's total expenses. The fund's investment in other funds advised by American Century Investments may create a conflict of interest for the fund's advisor.

Investments in the fund may be less tax-efficient than an investment in other ETFs because a significant portion of the fund's initial portfolio may consist of securities with a low tax basis. As a result, the fund may realize higher amounts of realized gains when selling securities and may be required to distribute capital gains.

Historically, small- and/or mid-cap stocks have been more volatile than the stock of larger, more-established companies. Smaller companies may have limited resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies.

International investing involves special risks, such as political instability and currency fluctuations. Investing in emerging markets may accentuate these risks.

The Russell 3000® Index is a trademark/service mark of the Frank Russell Company. Russell® is trademark of the Frank Russell Company.

Source: MSCI. Morgan Stanley Capital International (MSCI) makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

Exchange Traded Funds (ETFs): Foreside Fund Services, LLC - Distributor, not affiliated with American Century Investment Services, Inc.