UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number: 811-23402

Name and address of agent for service: John M. Perlowski, Chief Executive Officer, BlackRock ETF Trust, 55 East 52^nd Street, New York, NY 10055

Registrant’s telephone number, including area code: (800) 441-7762

Date of fiscal year end: 07/31/2021

Date of reporting period: 07/31/2021

(a) The Report to Shareholders is attached herewith.

BlackRock ETF Trust

Table of Contents

Investment Objective

The BlackRock Future Health ETF (the “Fund”) seeks to maximize total return.

Performance

GROWTH OF $10,000 INVESTMENT

(SINCE INCEPTION AT NET ASSET VALUE)

The inception date of the Fund was 9/29/20. The first day of secondary market trading was 10/1/20.

MSCI All Country World Index comprises large and mid-capitalization developed and emerging market equities.

Past performance is no guarantee of future results. Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. See “About Fund Performance” on page 14 for more information.

Expense Example

Portfolio Management Commentary

The stocks of innovative and emerging companies in the healthcare sector advanced during the reporting period. The medical devices and supplies sub-sector contributed the most to the Fund’s return.

Medical device companies with exposure to elective procedures benefited as a reduction on COVID-19 cases allowed hospitals to resume elective procedures. Devices used in nonemergency healthcare, like hearing aids, posted strong sales growth after pandemic-related restrictions were lifted, allowing care providers to reopen for less acute health needs. Life sciences tools and services companies also contributed meaningfully to the Fund’s performance. Contract research organizations benefited from demand for laboratory services from pharmaceuticals companies conducting research and development, particularly for coronavirus vaccine studies. The biotechnology industry contributed meaningfully, supported by regulatory approvals for several new cancer therapies and strategic collaborations for developing cancer and autoimmune treatments.

In terms of the largest individual drivers of performance, Chinese contract research organization WuXi Biologics was the largest individual stock contributor to the Fund’s return during the reporting period. The company benefited from increased demand for research and development services for coronavirus vaccine and treatment production. Switzerland-based Straumann Holding advanced amid consumer spending gains on elective procedures such as specialty dental treatments as pandemic-related restrictions were lifted. Leading individual detractors from the Fund’s return included two U.S.-based biotechnology companies. Seagen, a growth-oriented maker of antibody conjugates, was challenged by the reversal of market sentiment from growth to value. Forma Therapeutics’ stock also declined following pandemic-related delays in its clinical trial.

Portfolio Information

Investment Objective

The BlackRock Future Innovators ETF (the “Fund”) seeks long-term capital appreciation.

Performance

GROWTH OF $10,000 INVESTMENT

(SINCE INCEPTION AT NET ASSET VALUE)

The inception date of the Fund was 9/29/20. The first day of secondary market trading was 10/1/20.

Certain sectors and markets performed exceptionally well based on market conditions since the Fund commenced operations. Achieving such exceptional returns involves the risk of volatility and investors should not expect that such exceptional returns will be repeated.

The Russell 2500^™ Growth Index measures the performance of the small to mid-cap growth segment of the US equity universe. It includes those Russell 2500^™ companies with higher growth earning potential as defined by FTSE Russell’s leading style methodology.

Past performance is no guarantee of future results. Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. See “About Fund Performance” on page 14 for more information.

Expense Example

Portfolio Management Commentary

Stocks of innovative, small- and medium-capitalization growth companies advanced strongly for the reporting period, propelled by a recovering economy and the continuation of trends toward increasing automation. The health care sector was the leading contributor to the Fund’s return led by the biotechnology sub-sector and followed by the health care technology and pharmaceuticals sub-sectors. In health care technology, increased automation of patient check-in procedures at medical facilities, motivated in part by social distancing recommendations, drove gains among makers of platforms that manage patient intake.

Following health care, the industrials sector also contributed to the Fund’s performance. The electrical equipment industry as well as the aerospace & defense and machinery sub-sectors led returns for the sector. In addition to health care and industrials, information technology contributed to the Fund’s return, led by the software industry. The pandemic accelerated adoption of software that assists in managing office functions in an environment with many employees working online. As more businesses migrated office functions to cloud computing platforms, sales of software providing payroll and other back-office services to smaller businesses grew significantly. Semiconductors and semiconductor equipment stocks benefited from a global microchip shortage, which helped bolster profit margins at companies that provide materials for chip manufacturers.

In terms of relative performance, the Fund significantly outperformed the broader market, as represented by the Russell 2500 Growth Index. On a relative basis, the leading contributor to the Fund’s return was Plug Power, a developer of hydrogen-powered fuel-cell technologies. The company initiated ventures to develop alternative power systems for vehicles in South Korea and France and announced plans to build North America’s largest hydrogen facility in New York state. Amyris, a maker of synthetic chemicals, was another notable contributor to the Fund’s relative performance, benefiting from the economic recovery and the related rebound in consumer spending. Amyris creates and sells sustainable ingredients to use in products such as cosmetics and foods while continuing to expand its pipeline of ingredients in active development.

On the downside, Kahoot!, a company in the entertainment industry that creates educational technology platforms, detracted from the Fund’s relative performance. Slow organic growth constrained the Norwegian company, although it continued to make acquisitions during the reporting period, such as Clever, which makes educational portal software. Used car sales platform Vroom also weighed on the Fund’s relative return amid slowing revenue growth and labor constraints.

Portfolio Information

Investment Objective

The BlackRock Future Tech ETF (the “Fund”) seeks to maximize total return.

Performance

GROWTH OF $10,000 INVESTMENT

(SINCE INCEPTION AT NET ASSET VALUE)

The inception date of the Fund was 9/29/20. The first day of secondary market trading was 10/1/20.

Certain sectors and markets performed exceptionally well based on market conditions since the Fund commenced operations. Achieving such exceptional returns involves the risk of volatility and investors should not expect that such exceptional returns will be repeated.

MSCI All Country World Index comprises large and mid-capitalization developed and emerging market equities.

Past performance is no guarantee of future results. Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. See “About Fund Performance” on page 14 for more information.

Expense Example

Portfolio Management Commentary

The stocks of companies developing innovative and emerging technologies in the technology sector advanced significantly during the reporting period. The semiconductors industry contributed the most to the Fund’s return, driven in part by a global shortage of semiconductors as a fast-paced economic recovery boosted demand, putting pressure on supply. The most notable contributors within the semiconductors industry were semiconductor capital equipment manufacturers that benefitted from increased investments from foundries, as well as semiconductor manufacturers tied to secular growth themes such as the build out of 5G infrastructure and the broader adoption of electric vehicles.

Internet companies were another source of strength as many companies posted strong earnings and growth on the back of increased ad spending as a result of the economic recovery. The software industry also contributed to the Fund’s return. Cloud software companies experienced considerable growth over the period as the pandemic continued to accelerate the digital transformation of enterprises from on-premise computing to cloud computing.

A position in Canadian payment software provider Lightspeed was the largest individual stock contributor to return over the period. The company benefitted from the reopening of its merchant base and an increase in payments monetization. A position in US-based social media company Snap Inc was the second largest individual stock contributor to return over the period, as the company’s flagship app, Snapchat, saw high growth in both revenue and daily active users.

A position in Japanese cloud security SaaS provider Hennge KK was the largest individual stock detractor from return over the period, as the adoption of SaaS has picked up slower than expected in Japan. A position in US-based e-commerce company ContextLogic was the second largest individual stock detractor from performance over the period. The company’s stock came under pressure as the economic restart led to a deceleration of revenue growth.

Portfolio Information

Investment Objective

The BlackRock U.S. Carbon Transition Readiness ETF (the “Fund”) seeks long-term capital appreciation by investing in large- and mid-capitalization U.S. equity securities that may be better positioned to benefit from the transition to a low-carbon economy.

Performance

For the fiscal period ended 7/31/21, the Fund did not have six months of performance and therefore line graphs are not presented.

The inception date of the Fund was 4/6/21. The first day of secondary market trading was 4/8/21.

The Russell 1000^® Index measures the performance of the large-cap segment of the U.S. equity universe. It is a subset of the Russell 3000^® Index and includes approximately 1,000 of the largest securities based on a combination of their market capitalization and current index membership. The index represents approximately 92% of the total market capitalization of the Russell 3000^® Index.

Past performance is no guarantee of future results. Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. See “About Fund Performance” on page 14 for more information.

Expense Example

Portfolio Information

Investment Objective

The BlackRock U.S. Equity Factor Rotation ETF (the “Fund”) seeks to outperform the investment results of the large- and mid-capitalization U.S. equity markets by providing diversified and tactical exposure to style factors via a factor rotation model. The Fund is an actively managed exchange-traded fund and does not seek to replicate the performance of a specified index.

Performance

GROWTH OF $10,000 INVESTMENT

(SINCE INCEPTION AT NET ASSET VALUE)

The inception date of the Fund was 3/19/19. The first day of secondary market trading was 3/21/19.

Certain sectors and markets performed exceptionally well based on market conditions during the one-year period. Achieving such exceptional returns involves the risk of volatility and investors should not expect that such exceptional returns will be repeated.

The MSCI USA Index is designed to measure the performance of the large and mid cap segments of the US market. The index covers approximately 85% of the free float-adjusted market capitalization in the US. Effective September 23, 2019, the Fund changed its benchmark against which it measures its performance from a custom weighted index composed of the 80% MSCI USA Index / 20% MSCI USA Minimum Volatility (USD) Index to the MSCI USA Index.

Past performance is no guarantee of future results. Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. See “About Fund Performance” on page 14 for more information.

Expense Example

Portfolio Management Commentary

The Fund advanced for the reporting period, driven in large part by the information technology and consumer discretionary sectors. Among information technology stocks, the software and services industry gained, buoyed by an increase in investments to support remote work. Increased adoption of cloud computing, which provides a steady revenue stream for software makers, bolstered earnings in the industry. Sales of cloud products that build and deploy applications and services grew significantly, strengthening revenues in the industry. The semiconductors and semiconductor equipment industry benefited from a global microchip shortage and higher demand for advanced graphics cards amid an increase in gaming. The technology hardware and equipment industry also advanced as continued working and studying from home boosted demand for computers, mobile devices, and technology services.

The consumer discretionary sector was supported by robust consumer spending, which was particularly beneficial for automobiles and components manufacturers and retailers. Massive fiscal stimulus payments along with an improving employment landscape drove consumer spending, particularly among electric carmakers and multiline retailers.

Financials stocks were also meaningful contributors to the Fund’s return as robust retail stock trading and strong revenues from asset management and investment banking services benefited the diversified financials industry. Healthcare stocks gained amid development and distribution of coronavirus vaccines, which drove strong returns of biotechnology and pharmaceuticals stocks.

In terms of relative performance, the Fund outperformed the broader market, as represented by the MSCI USA Index. The Fund’s actively managed factor rotation strategy seeks diversified exposure to five style factors: value, low size, momentum, quality, and minimum volatility. The Fund seeks to outperform the broader market through the efficacy of these factors, as well as by actively emphasizing exposure to the factors that BlackRock Fund Advisors believes will perform best based on forward-looking insights.

The factors benefited the Fund’s relative performance as the value, low size, and quality factors outperformed the MSCI USA Index, while the minimum volatility and momentum factors trailed the broader market. The environment for factors with high sensitivity to economic growth, such as value and low size, improved as subsiding political uncertainty following the U.S. presidential election and vaccine rollouts heightened expectations for an economic recovery. The Fund’s factor tilting contributed to relative performance, driven primarily by limited exposure to the minimum volatility factor and overweight exposure to the low size factor.

Portfolio Information

Investment Objective

The BlackRock World ex U.S. Carbon Transition Readiness ETF (the “Fund”) seeks long-term capital appreciation by investing in large- and mid-capitalization World ex U.S. equity securities that may be better positioned to benefit from the transition to a low-carbon economy.

Performance

For the fiscal period ended 7/31/21, the Fund did not have six months of performance and therefore line graphs are not presented.

The inception date of the Fund was 4/6/21. The first day of secondary market trading was 4/8/21.

The MSCI World ex USA Index captures large- and mid-cap representation across certain developed markets countries, excluding the United States. The index covers approximately 85% of the free float-adjusted market capitalization in each country.

Past performance is no guarantee of future results. Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. See “About Fund Performance” on page 14 for more information.

Expense Example

Portfolio Information

Past performance is not an indication of future results. Financial markets have experienced extreme volatility and trading in many instruments has been disrupted. These circumstances may continue for an extended period of time and may continue to affect adversely the value and liquidity of the fund’s investments. As a result, current performance may be lower or higher than the performance data quoted. Performance data current to the most recent month-end is available at blackrock.com. Performance results assume reinvestment of all dividends and capital gain distributions and do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. The investment return and principal value of shares will vary with changes in market conditions. Shares may be worth more or less than their original cost when they are redeemed or sold in the market. Performance for certain funds may reflect a waiver of a portion of investment advisory fees. Without such a waiver, performance would have been lower.

Net asset value or “NAV” is the value of one share of a fund as calculated in accordance with the standard formula for valuing mutual fund shares. Beginning August 10, 2020, the price used to calculate market return (“Market Price”) is the closing price. Prior to August 10, 2020, Market Price was determined by using the midpoint between the highest bid and the lowest ask on the primary stock exchange on which shares of a fund are listed for trading, as of the time that such fund’s NAV is calculated. Since shares of a fund may not trade in the secondary market until after the fund’s inception, for the period from inception to the first day of secondary market trading in shares of the fund, the NAV of the fund is used as a proxy for the Market Price to calculate market returns. Market and NAV returns assume that dividends and capital gain distributions have been reinvested at Market Price and NAV, respectively.

An index is a statistical composite that tracks a specified financial market or sector. Unlike a fund, an index does not actually hold a portfolio of securities and therefore does not incur the expenses incurred by a fund. These expenses negatively impact fund performance. Also, market returns do not include brokerage commissions that may be payable on secondary market transactions. If brokerage commissions were included, market returns would be lower.

Shareholder Expenses

As a shareholder of your Fund, you incur two types of costs: (1) transaction costs, including brokerage commissions on purchases and sales of fund shares and (2) ongoing costs, including management fees and other fund expenses. The expense example, which is based on an investment of $1,000 invested at the beginning of the period (or from the commencement of operations if less than 6 months) and held through the end of the period, is intended to help you understand your ongoing costs (in dollars and cents) of investing in your Fund and to compare these costs with the ongoing costs of investing in other funds.

Actual Expenses – The table provides information about actual account values and actual expenses. Annualized expense ratios reflect contractual and voluntary fee waivers, if any. To estimate the expenses that you paid on your account over the period, simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number under the heading entitled “Expenses Paid During the Period.”

Hypothetical Example for Comparison Purposes – The table also provides information about hypothetical account values and hypothetical expenses based on your Fund’s actual expense ratio and an assumed rate of return of 5% per year before expenses. You may use this information to compare the ongoing costs of investing in your Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as brokerage commissions and other fees paid on purchases and sales of fund shares. Therefore, the hypothetical examples are useful in comparing ongoing costs only and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would have been higher.

Affiliates

Investments in issuers considered to be affiliate(s) of the Fund during the period ended July 31, 2021 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

Fair Value Measurements

Various inputs are used in determining the fair value of financial instruments. For description of the input levels and information about the Fund’s policy regarding valuation of financial instruments, refer to the Notes to Financial Statements.

The following table summarizes the value of the Fund’s investments according to the fair value hierarchy as of July 31, 2021. The breakdown of the Fund’s investments into major categories is disclosed in the Schedule of Investments above.

See notes to financial statements.