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.

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.

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.

Derivatives may be more sensitive to changes in market conditions and may amplify risks.

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.