Summary Prospectus by Investment Company (Form 497K)

Investment Objective

The investment objective of the Fund is to seek to track the investment results, before fees and expenses, of the ICE BofA BB-B U.S. Cash Pay High Yield Constrained Index.

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, when buying or selling shares of the Fund, which are not reflected in this table or the example that follows:

Annual Fund Operating Expenses

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

¹ Other Expenses are estimated for the current fiscal year.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all your shares at the end of a period. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The example does not reflect brokerage commissions that you may pay when you purchase and sell Fund shares. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. The Fund has not completed its first fiscal year, and therefore it does not have a portfolio turnover rate to report.

Principal Investment Strategies

The Fund seeks to track the investment results, before fees and expenses, of the ICE BofA BB-B U.S. Cash Pay High Yield Constrained Index (the "Index"), which is comprised of U.S. dollar-denominated below-investment grade publicly issued corporate debt in the U.S. that are currently in a coupon paying period and are rated BB1 through B3, based on an average of Moody's Investors Services, Inc. ("Moody's"), S&P Global Ratings ("S&P") and Fitch Ratings, Inc. ("Fitch"), but caps issuer exposure at 2%. Index constituents are capitalization-weighted, based on their current amount outstanding, provided the total allocation to an individual issuer does not exceed 2%. Issuers that exceed the limit are reduced to 2% and the face value of each of their bonds is adjusted on a pro-rata basis. Similarly, the face values of bonds of all other issuers that fall below the 2% cap are increased on a pro-rata basis. In the event there are fewer than 50 issuers in the Index, each is equally weighted and the face values of their respective bonds are increased or decreased on a pro-rata basis. A substantial portion of Index constituents may be restricted securities, including Rule 144A securities. Neither Nuveen Asset Management, LLC, the Fund's sub-adviser (the "sub-adviser") nor its affiliates have any discretion to select Index or Base Index components or change the Index's or Base Index's methodologies. As of July 31, 2025, the Index was comprised of 1,654 securities.

Accrued interest is calculated assuming next-day settlement. Cash flows from bond payments that are received during the month are retained in the index until the end of the month and then are removed as part of the rebalancing. Cash does not earn any reinvestment income while it is held in the Index. The Index is rebalanced on the last calendar day of the month, based on information available up to and including the third business day before the last business day of the month. Securities that meet the qualifying criteria are included in the Index for the following month. Securities that no longer meet the criteria during the course of the month remain in the Index until the next month-end rebalancing, at which point they are removed from the Index.

The Fund generally uses a representative sampling strategy to achieve its investment objective, meaning it generally invests in a sample of the securities in the Index whose risk, return and other characteristics resemble the risk, return and other characteristics of the Index as a whole. The Fund makes corresponding changes to its portfolio shortly after any Index changes are made public.

Under normal market conditions, the Fund invests at least 80% of the sum of its net assets and the amount of any borrowings for investment purposes in component securities of the Index. To the extent the Index concentrates (i.e., holds 25% or more of its total assets) in the securities of companies in a particular industry or group of industries, the Fund will concentrate its investments to approximately the same extent as the Index. The Fund may also invest up to 20% of its net assets in certain futures, options and swap contracts, U.S. Treasury obligations, U.S. Government obligations, U.S. agency securities, securities of other registered investment companies, cash and cash equivalents, as well as in securities not included in the Index, but which the sub-adviser believes will help the Fund track the Index.

The Fund is "non-diversified" and therefore is not required to meet certain diversification requirements under the Investment Company Act of 1940, as amended (the "1940 Act").

Principal Risks

The value of your investment in this Fund may change throughout the day on each day the Fund's primary listing exchange is open. You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks of investing in the Fund listed below are presented alphabetically to facilitate your ability to find particular risks and compare them with the risks of other funds. The significance of any specific risk to an investment in the Fund will vary over time depending on the composition of the Fund's portfolio, market conditions and other factors. Each risk summarized below is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears.

Call Risk-If, during periods of falling interest rates, an issuer exercises its right to prepay principal on its higher-yielding debt securities held by the Fund prior to the scheduled maturity date, the Fund may have to reinvest in securities with lower yields or higher risk of default, which may adversely impact the Fund's performance.

Cash Redemption Risk-The Fund's investment strategy may require it to effect redemptions, in whole or in part, in cash. In order to obtain the cash needed for a redemption, the Fund may be required to sell portfolio securities, which may cause the Fund to incur certain costs such as brokerage costs and recognize capital gains or losses that it might not have recognized if it had satisfied the redemption in-kind. Therefore, to the extent the Fund effects redemptions in cash, it may pay out higher annual capital gain distributions than if it satisfied redemptions entirely in-kind. These costs may decrease the Fund's NAV to the extent not offset by a transaction fee payable by an authorized participant.

Concentration Risk-To the extent that the Fund's portfolio is concentrated in the securities of issuers in a particular market, industry, group of industries or sector, the Fund may be adversely affected by the performance of those securities, may be subject to increased price volatility and may be more susceptible to adverse economic, market, political or regulatory occurrences affecting that market, industry, group of industries or sector.

Credit Risk-Credit risk is the risk that an issuer or other obligated party of a debt security may be, or perceived (whether by market participants, rating agencies, pricing services or otherwise) to be, unable or unwilling to make interest and principal payments when due and the related risk that the value of a debt security may decline because of concerns about the issuer's ability or willingness to make such payments. Because the Fund may invest without limitation in high yield securities, the Fund's credit risks are greater than those of funds that buy only investment grade securities.

Credit Spread Risk-Credit spread risk is the risk that credit spreads (i.e., the difference in yield between securities that is due to differences in their credit quality) may increase when the market believes that bonds generally have a greater risk of default. Increasing credit spreads may reduce the market values of the Fund's debt securities. Credit spreads often increase more for lower rated and unrated securities than for investment grade securities. In addition, when credit spreads increase, reductions in market value will generally be greater for longer-maturity securities.

Cybersecurity Risk-Cybersecurity risk is the risk of an unauthorized breach and access to Fund assets, customer data (including private shareholder information), or proprietary information, or the risk of an incident occurring that causes the Fund, its investment adviser or sub-adviser, custodian, transfer agent, distributor or other service provider, a financial intermediary or the issuers of securities held by the Fund to suffer a data breach, data corruption or lose operational functionality. Successful cyber-attacks or other cyber-failures or events affecting the Fund, its service providers or the issuers of securities held by the Fund may adversely impact the Fund or its shareholders. Additionally, a cybersecurity breach could affect the issuers in which the Fund invests, which may cause the Fund's investments to lose value.

High Yield Securities Risk-High yield securities, which are rated below investment grade and commonly referred to as "junk" bonds, and unrated securities of comparable quality are high risk investments that may cause income and principal losses for the Fund. They generally are considered to be speculative with respect to the ability to pay interest and repay principal, have greater credit risk, are less liquid, are more likely to experience a default and have more volatile prices than investment grade securities, especially during periods of uncertainty or market turmoil.

Illiquid Investments Risk-Certain securities held by the Fund could be or become illiquid investments, which may be difficult to sell for the value at which they are carried, if at all, or at any price within the desired time frame.

Income Risk-The Fund's income could decline during periods of falling interest rates or when the Fund experiences defaults on debt securities it holds.

Index Provider Risk-There is no assurance that the Index will be determined, maintained, constructed, reconstituted, rebalanced, composed, calculated or disseminated accurately. To correct any such error, an index provider may carry out an unscheduled rebalance or other modification of the Index constituents or weightings, which may increase the Fund's costs. Unusual market conditions may cause an index provider to postpone a scheduled rebalance. Such a postponement in a time of market volatility could mean a constituent that would otherwise be removed at rebalance may remain, causing the performance and constituents of the index to vary from those expected under normal conditions. Index providers generally do not provide any representation or warranty in relation to the quality, accuracy or completeness of data in the indexes in which they license, and generally do not guarantee that an index will be calculated in accordance with its stated methodology. Losses or costs associated with any index provider errors generally will be borne by the Fund and its shareholders.

Interest Rate Risk-Interest rate risk is the risk that the value of the Fund's fixed-rate securities will decline because of rising interest rates. Changing interest rates, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund's performance to the extent that it is exposed to such interest rates. Fixed-rate securities may be subject to a greater risk of rising interest rates than would normally be the case due to the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. Higher periods of inflation could lead to government fiscal policies which raise interest rates. When interest rates change, the values of fixed-rate securities with longer durations or maturities usually change more than the values of fixed-rate securities with shorter durations or maturities. Conversely, fixed-rate securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-rate securities with longer durations or maturities. Rising interest rates also may lengthen the duration of fixed-rate securities with call features, since exercise of the call becomes less likely as interest rates rise, which in turn will make the securities more sensitive to changes in interest rates and result in even steeper price declines in the event of further interest rate increases. The Fund is also subject to the risk that the income generated by its investments may not keep pace with inflation. There is a risk that interest rates across the financial system may change, possibly significantly and/or rapidly. In general, changing interest rates, including rates that fall below zero, or a lack of market participants may lead to decreased liquidity and increased volatility in the fixed-rate market, making it more difficult for the Fund to sell fixed-rate securities. Changes in interest rates may also lead to an increase in Fund redemptions, which may result in higher portfolio turnover costs, thereby adversely affecting the Fund's performance.

Market Risk-The market value of the Fund's investments may go up or down, sometimes rapidly or unpredictably and for short or extended periods of time, due to the particular circumstances of individual issuers or due to general conditions impacting issuers more broadly. Global economies and financial markets have become highly interconnected, and thus economic, market or political conditions or events in one country or region might adversely impact the value of the Fund's investments whether or not the Fund invests in such country or region. Events such as war, tariffs, sanctions, and other trade restrictions, terrorism, geopolitical events, financial system instability, natural and environmental disasters and the spread of infectious illnesses or other public health emergencies may have a severe negative impact on the global economy, could cause financial markets to experience extreme volatility and losses, and could result in the disruption of trading and the reduction of liquidity in many instruments. Additionally, to the extent the rate of inflation increases, the value of the Fund's assets may decline.

Market Liquidity Risk-Reductions in trading activity or dealer inventories of securities such as bonds, which provide an indication of the ability of financial intermediaries to "make markets" in those securities, have the potential to decrease liquidity and increase price volatility in the markets in which the Fund invests, particularly during periods of economic or market stress. In addition, federal banking regulations may cause certain dealers to reduce their inventories of securities, which may further decrease the Fund's ability to buy or sell securities. As a result of this decreased liquidity, the Fund may have to accept a lower price to sell a security, sell other securities to raise cash, or give up an investment opportunity, any of which could have a negative effect on performance. Although only certain institutional investors are entitled to redeem

shares of the Fund (as described in more detail under "Purchase and Sale of Fund Shares" below), if the Fund is forced to sell underlying investments at reduced prices or under unfavorable conditions to meet redemption requests or for other cash needs, the Fund may suffer a loss and hurt performance.

Market Trading Risks-The Fund is an exchange-traded fund ("ETF"), and as with all ETFs, Fund shares may be bought and sold in the secondary market at market prices. Although it is expected that the market price of a Fund share typically will approximate its net asset value ("NAV"), there may be times when the market price and the NAV diverge more significantly, particularly in times of market volatility or steep market declines. Thus, you may pay more or less than NAV when you buy Fund shares on the secondary market, and you may receive more or less than NAV when you sell those shares. Although the Fund's shares are listed for trading on a national securities exchange, it is possible that an active trading market may not develop or be maintained, in which case transactions may occur at wider bid/ask spreads (which may be especially pronounced for smaller funds). Trading of the Fund's shares may be halted by the activation of individual or market-wide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). In times of market stress, the Fund's underlying portfolio holdings may become less liquid, which in turn may affect the liquidity of the Fund's shares and/or lead to more significant differences between the Fund's market price and its NAV. Market makers are under no obligation to make a market in the Fund's shares, and authorized participants are not obligated to submit purchase or redemption orders for the Fund's shares. In the event market makers cease making a market in the Fund's shares or authorized participants stop submitting creation or redemption orders, Fund shares may trade at a larger premium or discount to NAV.

Non-Diversification Risk-As a non-diversified fund, the Fund may invest a larger portion of its assets in the securities of a limited number of issuers and may be more sensitive to any single economic, business, political or regulatory occurrence affecting an issuer than a diversified fund. Poor performance by any one of these issuers would adversely affect the Fund to a greater extent than a more broadly diversified fund.

Restricted Securities Risk-The market for restricted securities, including Rule 144A securities, typically is less active than the market for publicly traded securities. Rule 144A securities and other securities exempt from registration under the Securities Act carry the risk that their liquidity may become impaired and the Fund may be unable to dispose of the securities promptly or at current market value.

Service Provider Operational Risk-The Fund's service providers, such as the Fund's administrator, custodian or transfer agent, may experience disruptions or operating errors that could negatively impact the Fund. Although service providers are required to have appropriate operational risk management policies and procedures, and to take appropriate precautions to avoid and mitigate risks that could lead to disruptions and operating errors, it may not be possible to identify all of the operational risks that may affect the Fund or to develop processes and controls to completely eliminate or mitigate their occurrence or effects.

Tracking Error Risk-Tracking error is the divergence of the Fund's performance from that of the Index. Tracking error may occur because of, for example, pricing differences, transaction costs, the Fund's holding of uninvested cash, differences in timing of the accrual of distributions, changes to the Index or the need to meet various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. The Fund's use of a representative sampling strategy, as opposed to full replication, to achieve its investment objective may also result in increased tracking error. Tracking error also may result because the Fund incurs fees and expenses, but the Index does not.

Unrated Security Risk-Unrated securities determined by the Fund's sub-adviser to be of comparable quality to rated securities which the Fund may purchase may pay a higher interest rate than such rated securities and be subject to a greater risk of illiquidity or price changes. Less public information is typically available about unrated securities or issuers than rated securities or issuers.

Valuation Risk-The debt securities in which the Fund invests typically are valued by a pricing service utilizing a range of market-based inputs and assumptions, including price quotations obtained from broker-dealers making markets in such instruments, cash flows and transactions for comparable instruments. There is no assurance that the Fund will be able to buy or sell a portfolio security at the price established by the pricing service, which could result in a gain or loss to the Fund. Pricing services generally price debt securities assuming orderly transactions of an institutional "round lot" size, but some trades may occur in smaller, "odd lot" sizes, often at lower prices than institutional round lot trades. Over certain time periods, such differences could materially impact the performance of the Fund, which may not be sustainable. Alternative pricing services may incorporate different assumptions and inputs into their valuation methodologies, potentially resulting in different values for the same securities. As a result, if the Fund were to change pricing services, or

if the Fund's pricing service were to change its valuation methodology, there could be a material impact, either positive or negative, on the Fund's net asset value.

Fund Performance

The Fund is new and therefore does not have performance history for a full calendar year. When this prospectus is updated after a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Fund by showing the variability of the Fund's returns based on net assets and comparing the Fund's performance to a broad measure of market performance. Updated performance information is available at www.nuveen.com/etf or by calling (800) 257-8787.

Management

Investment Adviser

Nuveen Fund Advisors, LLC

Sub-Adviser

Nuveen Asset Management, LLC

Portfolio Managers

Purchase and Sale of Fund Shares

The Fund is an ETF. Shares of the Fund are listed on a national securities exchange and can only be bought and sold in the secondary market through a broker-dealer at market prices. Because Fund shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (at a "premium") or less than NAV (at a "discount"). An investor may also incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase Fund shares (bid) and the lowest price a seller is willing to accept for Fund shares (ask) when buying and selling shares in the secondary market (the "bid/ask spread"). Recent information regarding the Fund, including its NAV, market price, premiums and discounts, and bid/ask spreads, is available on the Fund's website at www.nuveen.com/etf.

Tax Information

The Fund's distributions are taxable and will generally be taxed as ordinary income or capital gains, unless you are investing through a tax-deferred account, such as an individual retirement account ("IRA") or 401(k) plan (in which case you may be taxed upon withdrawal of your investment from such account).

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a broker-dealer or other financial intermediary (such as a bank or financial advisor), the Fund's investment adviser or its affiliates may pay the intermediary for marketing activities and presentations, educational training programs, conferences, the development of technology platforms and reporting systems or other services related to the sale or promotion of Fund shares. These payments may create a conflict of interest by influencing the broker-dealer or other financial intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.