Form 497K BlackRock ETF Trust

Portfolio Turnover. The Fund may pay 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 the Annual Fund Operating Expenses or in the Example, affect the Fund’s performance. From inception (September 29, 2020) to the most recent fiscal year end, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Principal Investment Strategies

Under normal market conditions, the Fund will invest at least 80% of its net assets plus any borrowings for investment purposes in equity securities of companies principally engaged in the health sciences group of industries.

The Fund will consider a company to be principally engaged in the health sciences group of industries if (i) it is classified in an industry within the health sciences group of industries by a third-party industry classification system or (ii) it is not classified in any industry by such third-party industry classification system and BFA determines that the company is principally engaged in the health sciences group of industries.

Companies in the health sciences group of industries include health care providers as well as businesses involved in researching, developing, producing, distributing or delivering medical, dental, optical, pharmaceutical

or biotechnology products, supplies, equipment or services or that provide support services to these companies. These companies also include those that own or operate health facilities and hospitals or provide related administrative, management or financial support. Other companies in the health sciences group of industries in which the Fund may invest include: clinical testing laboratories; diagnostics; hospital, laboratory or physician ancillary products and support services; rehabilitation services; employer health insurance management services; and vendors of goods and services specifically to companies engaged in the health sciences. The Fund will concentrate its investments in the health sciences group of industries.

While the Fund will invest primarily in companies providing products and services for human health, it may also invest in companies whose products or services relate to the growth or survival of animals and plants. Non-human health sciences companies include those engaged in the development, production or distribution of products or services that: increase crop, animal and animal product yields by enhancing growth or increasing disease resistance; improve agricultural product characteristics, such as taste, appearance, nutritional content and shelf life; reduce the cost of producing agricultural products; or improve pet health.

The Fund may invest in companies of any market capitalization located anywhere in the world, including companies located in emerging markets. The Fund will focus its investments in mid- and small-capitalization companies.

Foreign securities in which the Fund may invest may be U.S. dollar-denominated or non-U.S. dollar-denominated.

The Fund invests primarily in equity securities, including common stocks, preferred stocks, convertible securities, warrants and depository receipts, of health sciences companies and limited partnership interests in real estate investment trusts (“REITs”) that own hospitals. The Fund may invest in shares of companies through initial public offerings (“IPOs”).

During temporary defensive periods (i.e., in response to adverse market, economic or political conditions), the Fund may invest up to 100% of its total assets in liquid, short-term investments, including high quality, short-term securities. The Fund may not achieve its investment objectives under these circumstances. BFA’s determination that it is temporarily unable to follow the Fund’s investment strategy or that it is impractical to do so will generally occur only in situations in which a market disruption event has occurred and where trading in the securities selected through application of the Fund’s investment strategy is extremely limited or absent.

The Fund may purchase and sell futures contracts, enter into various interest rate transactions such as swaps, caps, floors or collars, currency transactions such as currency forward contracts, currency futures contracts, currency swaps or options on currency or currency futures and swap contracts (including, but not limited to, credit default swaps) and may purchase and sell exchange-listed and over-the-counter (“OTC”) put and call options on securities and swap

contracts, financial indices and futures contracts and use other derivative instruments or management techniques (collectively, “Strategic Transactions”). The Fund may engage in Strategic Transactions for duration management and other risk management purposes, including to attempt to protect against possible changes in the market value of the Fund’s portfolio resulting from trends in the securities markets and changes in interest rates or to protect the Fund’s unrealized gains in the value of its portfolio securities, to facilitate the sale of portfolio securities for investment purposes, to establish a position in the securities markets as a temporary substitute for purchasing particular securities or to enhance income or gain.

The Fund may invest up to 20% of its net assets plus any borrowings for investment purposes in other investments, including equity securities issued by companies that are not principally engaged in the health sciences group of industries and debt securities issued by any issuer, including non-investment grade debt securities. The Fund’s investments in non-investment grade securities and those deemed by Fund management to be of similar quality are considered speculative with respect to the issuer’s capacity to pay interest and repay principal and are commonly referred to as “junk” or “high yield” securities.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Summary of Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. Unlike many exchange-traded funds (“ETFs”), the Fund is not an index-based ETF. The order of the below risk factors does not indicate the significance of any particular risk factor.

Asset Class Risk. Securities and other assets in the Fund’s portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes.

Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the prospectus (the “Prospectus”)), a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time in order to facilitate commencement of the Fund’s operations or to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund.

Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is

obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem, Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting. Authorized Participant concentration risk may be heightened for ETFs, such as the Fund, that invest in securities issued by non-U.S. issuers or other securities or instruments that have lower trading volumes.

Biopharmaceuticals Industry Risk. Companies in the biopharmaceuticals industry may be highly volatile and affected by industry competition, dependency on a limited number of products, obsolescence of products, government approvals and regulations, loss or impairment of intellectual property rights and litigation regarding product liability.

Biotechnology Industry Risk. Companies in the biotechnology industry, as traditionally defined, face intense competition and potentially rapid product obsolescence. Biotechnology companies may be adversely affected by the loss or impairment of intellectual property rights or changes in government regulations.

Concentration Risk. The Fund may be susceptible to loss due to adverse events that affect the Fund’s investments more than the market as a

whole, to the extent that the Fund’s investments are concentrated in the securities and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Convertible Securities Risk. The market price of a convertible security generally tends to behave like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest, principal or dividends when due, and their market value may change based on changes in the issuer’s credit rating or the market’s perception of the issuer’s creditworthiness. Because a convertible security derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock, including the potential for increased volatility in the price of the convertible security.

Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund’s adviser, distributor, and other service providers (including the benchmark provider), market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system

breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests.

Depositary Receipts Risk. The Fund will invest in stocks of foreign corporations. The Fund’s investment in such stocks will be in the form of depositary receipts including American Depositary Receipts (“ADRs”) and Global Depositary Receipts (“GDRs”). While the use of ADRs and GDRs, which are traded on exchanges and represent an ownership in a foreign security, provide an alternative to directly purchasing the underlying foreign securities in their respective markets and currencies, investments in ADRs and GDRs continue to be subject to many of the risks associated with investing directly in foreign securities, including political, economic, and currency risk.

Derivatives Risk. The Fund may invest in certain types of derivatives contracts, including futures, options and swaps, which can be more sensitive to changes in interest rates or to sudden fluctuations in market prices than conventional securities, which can result in greater losses to the Fund.

Equity Securities Risk. Equity securities are subject to changes in value, and their values may be more volatile than those of other asset classes. Common stocks generally subject their holders to more risks than preferred stocks and debt securities because common stockholders’ claims are subordinated to those of holders of

preferred stocks and debt securities upon the bankruptcy of the issuer.

Forward Foreign Currency Exchange Contracts. Forward foreign currency exchange transactions are OTC contracts to purchase or sell a specified amount of a specified currency or multinational currency unit at a price and future date set at the time of the contract. Forward foreign currency exchange contracts do not eliminate fluctuations in the value of non-U.S. securities but rather allow the Fund to establish a fixed rate of exchange for a future point in time. This strategy can have the effect of reducing returns and minimizing opportunities for gain.

Futures Contract Risk. Futures are standardized, exchange-traded contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of an asset at a specified future date at a specified price. Unlike equities, which typically entitle the holder to a continuing ownership stake in a corporation, futures contracts normally specify a certain date for settlement in cash based on the level of the reference rate. The primary risks associated with the use of futures contracts, or swaps or other derivatives referencing futures contracts, are: (i) the imperfect correlation between the change in market value of the instruments held by the Fund and the price of the futures contract; (ii) possible lack of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (iii) losses caused by unanticipated market movements, which are potentially unlimited; (iv) BFA’s inability to predict

correctly the direction of prices and other economic factors; and (v) the possibility that the counterparty will default in the performance of its obligations.

Healthcare Sector Risk. The profitability of companies in the healthcare sector, including healthcare equipment and services companies, may be affected by government regulations and government healthcare programs, increases or decreases in the cost of medical products and services, an increased emphasis on outpatient services, demand for medical products and services and product liability claims, among other factors. Many healthcare companies are heavily dependent on patent protection, and the expiration of a company’s patent may adversely affect that company’s profitability. Healthcare companies are subject to competitive forces that may result in price discounting, and may be thinly capitalized and susceptible to product obsolescence.

High Portfolio Turnover Risk. The Fund may engage in active and frequent trading of its portfolio securities. High portfolio turnover (considered by the Fund to mean higher than 100% annually) may result in increased transaction costs to the Fund, including brokerage commissions, dealer mark-ups and other transaction costs on the sale of the securities and on reinvestment in other securities, as well as possible increased taxable distributions.

Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare

systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts.

Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. Changes in the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline.

Large-Capitalization Companies Risk. Large-capitalization companies may be less able than smaller capitalization companies to adapt to changing market conditions. Large-capitalization companies may be more mature and subject to more limited growth potential compared with smaller capitalization companies. During different market cycles, the performance of large-capitalization companies has trailed the overall performance of the broader securities markets.

Life Sciences Sector Risk. The life sciences sector is comprised primarily of companies focused on developing and selling biopharmaceutical products. The life sciences sector is heavily influenced by technology, government funding, government regulation, efforts by governments, healthcare providers

and health plans to reduce costs, changing consumer demographics and intellectual property rights, among other factors. Life sciences companies may be highly volatile and their products and services may experience rapid obsolescence due to a number of factors. The success of such companies may depend upon a relatively small number of products or services with long development cycles and large capital requirements that have a high chance of failure. In addition, changes in patent protection, shifting government regulations or regulatory attitudes, patent infringement or medical litigation may adversely affect the value of such companies.

Management Risk. The Fund is subject to management risk, which is the risk that the investment process, techniques and analyses applied by BFA will not produce the desired results, and those securities or other financial instruments selected by BFA may result in returns that are inconsistent with the Fund’s investment objective. In addition, legislative, regulatory, or tax developments may affect the investment techniques available to BFA in connection with managing the Fund and may also adversely affect the ability of the Fund to achieve its investment objective.

Market Risk. The Fund could lose money over short periods due to short-term market movements and over longer periods during more prolonged market downturns. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments

and could result in increased premiums or discounts to the Fund’s NAV.

Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. Unlike some ETFs that track specific indexes, the Fund does not seek to replicate the performance of a specified index. Index-based ETFs have generally traded at prices that closely correspond to NAV per share. Given the high level of transparency of the Fund’s holdings, BFA believes that the trading experience of the Fund should be similar to that of index-based ETFs. However, ETFs that do not seek to replicate the performance of a specified index have a limited trading history and, therefore, there can be no assurance as to whether, and/or the extent to which, the Fund’s shares will trade at premiums or discounts to NAV. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND’S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Mid-Capitalization Companies Risk. Compared to large-capitalization companies, mid-capitalization companies may be less stable and more susceptible to adverse developments. In addition, the securities of mid-capitalization companies may be more volatile and less liquid than those of large-capitalization companies.

“New Issues” Risk. “New issues” are IPOs of equity securities. Securities issued in IPOs have no trading history, and information about the companies

may be available for very limited periods. In addition, the prices of securities sold in IPOs may be highly volatile or may decline shortly after the IPO.

Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund’s performance may depend on the performance of a small number of issuers.

Non-U.S. Securities Risk. Investments in the securities of non-U.S. issuers are subject to the risks associated with investing in those non-U.S. markets, such as heightened risks of inflation or nationalization. The Fund may lose money due to political, economic and geographic events affecting issuers of non-U.S. securities or non-U.S. markets. In addition, non-U.S. securities markets may trade a small number of securities and may be unable to respond effectively to changes in trading volume, potentially making prompt liquidation of holdings difficult or impossible at times.

Operational Risk. The Fund is exposed to operational risks arising from a number of factors, including, but not limited to, human error, processing and communication errors, errors of the Fund’s service providers, counterparties or other third parties, failed or inadequate processes and technology or systems failures. The Fund and BFA seek to reduce these operational risks through controls and procedures. However, these measures do not address every possible risk and may be inadequate to address significant operational risks.

Options. An option is an agreement that, for a premium payment or fee, gives the option holder (the purchaser) the right but not the obligation to buy (a “call option”) or sell (a “put option”) the underlying asset (or settle for cash in an amount based on an underlying asset, rate, or index) at a specified price (the “exercise price”) during a period of time or on a specified date. Investments in options are considered speculative. When the Fund purchases an option, it may lose the total premium paid for it if the price of the underlying security or other assets decreased, remained the same or failed to increase to a level at or beyond the exercise price (in the case of a call option) or increased, remained the same or failed to decrease to a level at or below the exercise price (in the case of a put option). If a put or call option purchased by the Fund were permitted to expire without being sold or exercised, its premium would represent a loss to the Fund. To the extent that the Fund writes or sells an option, if the decline or increase in the underlying asset is significantly below or above the exercise price of the written option, the Fund could experience a substantial loss.

Preferred Stock Risk. Preferred stocks are subject not only to issuer-specific and market risks generally applicable to equity securities, but also risks associated with fixed-income securities, such as interest rate risk. A company’s preferred stock, which may pay fixed or variable rates of return, generally pays dividends only after the company makes required payments to creditors, including vendors, depositors, counterparties, holders of its bonds and other fixed-income securities. As a result, the value of a company’s

preferred stock will react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects. Preferred stock may be less liquid than many other types of securities, such as common stock, and generally has limited or no voting rights. Preferred stock generally does not reflect the performance of a company as directly as the company’s common stock. In addition, preferred stock is subject to the risks that a company may defer or not pay dividends, and, in certain situations, may call or redeem its preferred stock or convert it to common stock. An issuer may decide to call its outstanding preferred stock in various environments based on its assessment of the relative cost of capital across the company’s capital structure. A market-wide increase in preferred stock being called may reduce the aggregate size of the preferred stock universe and the number of issuers with preferred stock outstanding. To the extent that the Fund invests a substantial portion of its assets in convertible preferred stocks, declining common stock values may also cause the value of the Fund’s investments to decline.

Real Estate Investment Risk. The Fund may invest in companies that invest in, develop, or operate real estate (“Real Estate Companies”) such as REITs, which expose investors in the Fund to the risks of owning real estate directly, as well as to risks that relate specifically to the way in which Real Estate Companies are organized and operated. Real estate is highly sensitive to general and local economic conditions and developments, and characterized by intense competition and periodic overbuilding. Many Real

Estate Companies, including REITs, utilize leverage (and some may be highly leveraged), which increases investment risk and the risk normally associated with debt financing, and could potentially magnify the Fund’s losses. Rising interest rates could result in higher costs of capital for Real Estate Companies, which could negatively affect a Real Estate Company’s ability to meet its payment obligations or its financing activity and could decrease the market prices for REITs and for properties held by such REITs.

Risk of Investing in Emerging Markets. Investments in emerging markets may be subject to a greater risk of loss than investments in issuers located or operating in more developed markets. Emerging markets may be more likely to experience inflation, political turmoil and rapid changes in economic conditions than more developed markets. Companies in many emerging markets are not subject to the same degree of regulatory requirements, accounting standards or auditor oversight as companies in more developed countries, and as a result, information about the securities in which the Fund invests may be less reliable or complete. Emerging markets often have less reliable securities valuations and greater risk associated with custody of securities than developed markets. There may be significant obstacles to obtaining information necessary for investigations into or litigation against companies and shareholders may have limited legal remedies. Although the Fund is actively managed, investments are not generally selected based on investor protection limitations or differences in the quality of financial reporting and available oversight mechanisms.

Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

Risk of Swap Agreements. A swap is a two-party contract that generally obligates each counterparty to exchange periodic payments based on a pre-determined underlying investment or notional amount and to exchange collateral to secure the obligations of each counterparty. Swaps may be leveraged and are subject to counterparty risk, credit risk and pricing risk. Swaps may be subject to illiquidity risk, and it may not be possible for the Fund to liquidate a swap position at an advantageous time or price, which may result in significant losses. Certain standardized interest rate and credit default swaps are required to be traded on an exchange or trading platform and centrally cleared. Most other swaps are entered into a negotiated, bi-lateral basis and traded in the OTC market. Swaps are subject to bi-lateral variation margin. Initial margin requirements are in the process of being phased in, and the Fund may be subject to such requirements as early as September 2021.

Securities Lending Risk. The Fund may engage in securities lending. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund could also lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral.

These events could also trigger adverse tax consequences for the Fund.

Small-Capitalization Companies Risk. Compared to mid- and large-capitalization companies, small-capitalization companies may be less stable and more susceptible to adverse developments. In addition, the securities of small-capitalization companies may be more volatile and less liquid than those of mid- and large-capitalization companies.

Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders.

Tax Risk. The Fund invests in derivatives. The federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset. Derivatives may produce taxable income and taxable realized gain. Derivatives may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than as capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. Income

from swaps is generally taxable. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the U.S. Internal Revenue Service (“IRS”).

Warrants Risk. If the price of the underlying stock does not rise above the exercise price before the warrant expires, the warrant generally expires without any value and the Fund will lose any amount it paid for the warrant. Thus, investments in warrants may involve substantially more risk than investments in common stock. Warrants may trade in the same markets as their underlying stock; however, the price of the warrant does not necessarily move with the price of the underlying stock.

Performance Information

As of the date of this Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information. The Fund’s benchmark is MSCI ACWI Index.

Management

Investment Adviser. BlackRock Fund Advisors.

Portfolio Managers. Erin Xie, Jeff Lee and Xiang Liu (the “Portfolio Managers”) are jointly and primarily responsible for the day-to-day management of the Fund. Each Portfolio Manager supervises a portfolio management team. Ms. Xie and Messrs. Lee and Liu have been Portfolio Managers of the Fund since September 2020.

Purchase and Sale of Fund Shares

This Fund is an ETF. Individual shares of the Fund may only be bought and sold in the secondary market through a broker-dealer. Because ETF shares trade at market prices rather than at NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares of the Fund (bid) and the lowest price a seller is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (the “bid-ask spread”).

Tax Information

The Fund intends to make distributions that may be taxable to you as ordinary income or capital gains, unless you are investing through a tax-deferred arrangement such as a 401(k) plan or an individual retirement account (“IRA”), in which case, your distributions generally will be taxed when withdrawn.

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), BFA or other related companies 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 the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.