Summary Prospectus by Investment Company (Form 497K)

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. For the fiscal year ended July 31, 2025, the Fund's portfolio turnover rate was 40% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to outperform the price and yield performance of the Russell 1000^® Index (the "Underlying Index") before including Fund expenses by emphasizing Low Carbon Economy Transition Readiness ("LCETR") score criteria based on proprietary BlackRock

Fund Advisors ("BFA") research. The Fund seeks to maintain an LCETR score that is at least 10% better than that of its Underlying Index (the "uplift target"). This assessment versus the Underlying Index is determined at the time of investment and the Fund may deviate from its uplift target due to, among other factors, market movements or changes in data.

Under normal circumstances, the Fund seeks to invest at least 80% of its net assets plus the amount of any borrowings for investment purposes in equity securities of issuers listed in the United States of America. Investments in derivatives are counted toward the Fund's 80% policy to the extent that they provide investment exposure to the securities included within that policy or to one or more market risk factors associated with such securities. The Fund's 80% investment policy may be changed by the Fund's Board of Trustees (the "Board") upon 60 days' notice to shareholders.

The Fund selects portfolio securities that are components of the Underlying Index. The Underlying Index measures the performance of the large- and mid-capitalization sectors of the U.S. equity market, as defined by FTSE Russell (the "Index Provider" or "Russell"). The components of the Underlying Index are likely to change over time. The Fund may or may not hold all of the securities in the Underlying Index.

The Fund utilizes BFA's proprietary LCETR strategy to overweight, relative to the Underlying Index, issuers that BFA believes are best positioned to benefit from the transition to a low-carbon economy, and to underweight issuers that it believes are poorly positioned to so benefit. BFA assigns a transition readiness (or LCETR) score to each issuer by aggregating research-driven insights across different sustainability themes, which may include, but are not limited to, energy production, clean technology, energy management, waste management and water management. Although a majority of the LCETR score will be comprised of environmental considerations, the score will also incorporate social and governance considerations, as well as certain non-sustainability signals, including financial signals. The weighting of these inputs is determined and dynamically adjusted by BFA based on their assessed relative importance and prevailing market conditions. BFA uses the final score for each issuer to determine whether the Fund should overweight or underweight such issuer based on the issuer's score in comparison to other issuers in the peer industry. BFA's methodology seeks to emphasize the Fund's exposure to issuers with the highest LCETR scores while controlling for risk.

The Fund may invest in issuers in all industries represented in the Fund's Underlying Index, including those issuers that could be considered outside of LCETR investing.

The Fund may invest in large- and mid-capitalization companies.

Equity securities in which the Fund may invest include common stocks, preferred stocks, warrants, depositary receipts, exchange-traded funds ("ETFs") and equity interests in real estate investment trusts ("REITs") and master limited partnerships ("MLPs"). The Fund may also purchase convertible securities.

The Fund may invest in certain futures, options and swap contracts.

The Underlying Index is sponsored by Russell, which is part of the London Stock Exchange Group and is independent of the Fund and BFA. Russell determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index.

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 ETFs, the Fund is not an index-based ETF. Certain key risks are prioritized below (with others following in alphabetical order), but the relative

significance of any risk is difficult to predict and may change over time. You should review each risk factor carefully.

Equity Securities Risk. Stock markets are volatile. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions.

Sustainability Risk. Sustainability risk is an inclusive term to designate investment risk (probability or uncertainty of occurrence of material losses relative to the expected return of an investment) that relates to environmental, social or governance issues.

Sustainability risk around environmental issues includes, but is not limited to, climate risk, both physical and transition risk. Physical risk arises from the physical effects of climate change, acute or chronic. For example, frequent and severe climate-related events can impact products and services and supply chains. Transition risk - whether policy, technology, market or reputation risk - arises from the adjustment to a low-carbon economy in order to mitigate climate change. Risks related to social issues can include, but are not limited to, labor rights and community relations. Governance-related risks can include but are not limited to risks around board independence, ownership and control, and audit and tax management. These risks can impact an issuer's operational effectiveness and resilience as well as its public perception and reputation, affecting its profitability and, in turn, its capital growth and ultimately impacting the value of holdings in the Fund.

These are only examples of sustainability risk factors, and sustainability risk factors do not solely determine the risk profile of the investment. The relevance, severity, materiality and time horizon of sustainability risk factors and other risks can differ significantly across funds.

Sustainability risk can manifest itself through different existing risk types including, but not limited to, market, liquidity, concentration, credit and asset-liability mismatch risk. For example, the Fund may invest in the securities of an issuer that could face potentially reduced revenues or increased expenditures from physical climate risk (e.g., decreased production capacity due to supply chain perturbations, lower sales due to demand shocks or higher operating or capital costs) or transition risk (e.g., decreased demand for carbon-intensive products and services or increased production costs due to changing input prices). As a result, sustainability risk factors may have a material impact on an investment, may increase volatility, may affect liquidity and may have an adverse impact on the value of shares of the Fund.

The impact of those risks may be higher for funds with particular sectoral or geographic concentrations. For example, funds with geographic concentration in locations susceptible to adverse weather conditions where the value of the investments in the funds may be more susceptible to adverse physical climate events, or funds with specific sectoral concentrations, such as investing in industries or issuers with high carbon intensity or high switching costs

associated with the transition to low carbon alternatives, may be more impacted by climate transition risks.

All or a combination of these factors may have an unpredictable impact on the Fund's investments. Under normal market conditions, such events could have a material impact on the value of shares of the Fund.

Assessments of sustainability risk are specific to the asset class and to a fund's investment objective. Different asset classes require different data and tools to apply heightened scrutiny, assess materiality, and make meaningful differentiation among issuers and assets. To the extent consistent with the Fund's investment objective, risks are considered and risk managed concurrently, by prioritizing in part based on materiality and on the Fund's objective.

The impacts of sustainability risk are likely to develop over time, and new sustainability risks may be identified as further data and information regarding sustainability factors and impacts become available.

Low Carbon Exposure Investment Strategy Risk. The Fund's strategy of investing in securities of companies with low carbon exposure limits the type and number of investment opportunities available to the Fund and, as a result, the Fund may underperform other funds that do not seek to minimize carbon exposure. The Fund's low carbon exposure investment strategy may result in the Fund investing in securities or industry sectors that underperform the market.

Risk of Investing in the United States. 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.

Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Fund's prospectus), a third-party investor, the Fund's adviser, an affiliate of the Fund's adviser, or another fund may invest in the Fund and hold its investment for a specific period of time 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. There are a limited number of institutions that may act as Authorized Participants for the Fund, including on an agency basis on behalf of other market participants. No Authorized Participant is obligated to engage in creation or redemption transactions. To the extent that Authorized Participants exit the business or do not place creation or redemption orders for the Fund and no other Authorized Participant places orders, Fund shares are more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.

Convertible Securities Risk. The market value of a convertible security performs 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. Since it 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.

Depositary Receipts Risk. Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. In addition to investment risks associated with the underlying issuer, depositary receipts expose the Fund to additional risks associated with the non-uniform terms that apply to depositary receipt programs, credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency risk and the risk of an illiquid market for depositary receipts. The issuers of unsponsored depositary receipts are not obligated to disclose information that is, in the United States, considered material. Therefore, there may be less information available regarding these issuers and there may not be a correlation between such information and the market value of the depositary receipts. While depositary receipts provide an alternative to directly purchasing underlying foreign securities in their respective markets and currencies, they 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's use of derivatives may increase its costs, reduce the Fund's returns and/or increase volatility. Derivatives involve significant risks, including:

Leverage Risk. The Fund's use of derivatives can magnify the Fund's gains and losses. Relatively small market movements may result in large changes in the value of a derivatives position and can result in losses that greatly exceed the amount originally invested.

Market Risk. Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BFA may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund's derivatives positions to lose value.

Counterparty Risk. Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will be unable or unwilling to fulfill its contractual obligation, and the related risks of having concentrated exposure to such a counterparty.

Illiquidity Risk. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Operational Risk. The use of derivatives includes the risk of potential operational issues, including documentation issues, settlement issues, systems failures, inadequate controls and human error.

Legal Risk. The risk of insufficient documentation, insufficient capacity or authority of counterparty, or legality or enforceability of a contract.

Volatility and Correlation Risk. Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund's use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.

Valuation Risk. Valuation for derivatives may not be readily available in the market. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them.

Hedging Risk. Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund's hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences.

Tax Risk. Certain aspects of the tax treatment of derivative instruments, including swap agreements and commodity-linked derivative instruments, are currently unclear and may be affected by changes in legislation, regulations or other legally binding authority. Such treatment may be less favorable than that given to a direct investment in an underlying asset

and may adversely affect the timing, character and amount of income the Fund realizes from its investments.

ESG Screening Risk. The Fund intends to screen out particular issuers pursuant to certain criteria established by BlackRock. The Fund may forgo certain investment opportunities by screening out such issuers, and the Fund's results may be lower than other funds that do not apply exclusionary screens or use different ESG-related screening criteria. Further, investors may differ in their views of what constitutes positive or negative ESG characteristics of an issuer. As a result, the Fund may invest in issuers that do not reflect the beliefs of any particular investor. In evaluating an issuer based on ESG criteria, BlackRock is dependent upon certain information and data from third party providers of ESG research, which may be incomplete, inaccurate or unavailable. As a result, there is a risk that BlackRock may incorrectly assess an issuer. There is also a risk that BlackRock may not apply the relevant ESG criteria correctly or that a Fund could have indirect exposure to issuers who do not meet the relevant ESG criteria used by such Fund. Neither the Fund nor BlackRock make any representation or warranty, express or implied, with respect to the fairness, correctness, accuracy, reasonableness or completeness of such ESG criteria.

Investment in Other Investment Companies Risk. As with other investments, investments in other investment companies, including ETFs, are subject to market and selection risk. In addition, if the Fund acquires shares of investment companies, including ones affiliated with the Fund,

shareholders bear both their proportionate share of expenses in the Fund (including management and advisory fees) and, indirectly, the expenses of the investment companies (to the extent not offset by BFA through waivers). To the extent the Fund is held by an affiliated fund, the ability of the Fund itself to hold other investment companies may be limited.

Issuer Risk. Fund performance 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 Shareholder and Large-Scale Redemption Risk. Certain shareholders, including an Authorized Participant, a third-party investor, the Fund's adviser or an affiliate of the Fund's adviser, a market maker, or another entity, may from time to time own or manage a substantial amount of Fund shares, or may invest in the Fund and hold their investment for a limited period of time. There can be no assurance that any large shareholder or large group of shareholders would not redeem their investment.

Redemptions of a large number of Fund shares could require the Fund to dispose of assets to meet the redemption requests, which can accelerate the realization of taxable income and/or capital gains and cause the Fund to make taxable distributions to its shareholders earlier than the Fund otherwise would have. In addition, under certain circumstances, non-redeeming shareholders may be treated as receiving a disproportionately large taxable distribution during or with respect to such year. In some

circumstances, the Fund may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns. To the extent the Fund permits redemptions in cash, these large redemptions may also force the Fund to sell portfolio securities when it might not otherwise do so, which may negatively impact the Fund's NAV, increase the Fund's brokerage costs and/or have a material effect on the market price of the Fund shares.

Leverage Risk. Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet the applicable requirements of the Investment Company Act of 1940, as amended, and the rules thereunder. Increases and decreases in the value of the Fund's portfolio will be magnified when the Fund uses leverage.

Market Risk and Selection Risk. Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. 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. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.

Market Trading Risk.The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares (including through a trading halt), losses from trading in secondary markets, periods of high volatility, and disruptions in the process of creating and redeeming Fund shares. Any of these factors, among others, may lead to the Fund's shares trading in the secondary market at a premium or discount to NAV or to the intraday value of the Fund's portfolio holdings. If you buy Fund shares at a time when the market price is at a premium to NAV or sell Fund shares at a time when the market price is at a discount to NAV, you may pay significantly more or receive significantly less than the underlying value of the Fund shares.

Master Limited Partnerships Risk. The common units of an MLP are listed and traded on U.S. securities exchanges and their value fluctuates predominantly based on prevailing market conditions and the success of the MLP. Unlike owners of common stock of a corporation, owners of common units have limited voting rights and have no ability to annually elect directors. In the event of liquidation,

common units have preference over subordinated units, but not over debt or preferred units, to the remaining assets of the MLP.

Mid Cap Securities Risk. The securities of mid cap companies generally trade in lower volumes and are generally subject to greater and less predictable price changes than the securities of larger capitalization companies.

Operational and Technology Risks. The Fund is directly and indirectly susceptible to operational and technology risks, including those related to human errors, processing errors, communication errors, systems failures, cybersecurity incidents, and the use of artificial intelligence and machine learning ("AI"), which may result in losses for the Fund and its shareholders or may impair the Fund's operations. While the Fund's service providers are required to have appropriate operational, information security and cybersecurity risk management policies and procedures, their methods of risk management may differ from those of the Fund. Operational and technology risks for the issuers in which the Fund invests could also result in material adverse consequences for such issuers and may cause the Fund's investments in such issuers to lose value.

Preferred Securities Risk. Preferred securities may pay fixed or adjustable rates of return. Preferred securities are subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company's preferred securities generally pay dividends only after the company makes required payments to holders of its bonds and other debt. For this

reason, the value of preferred securities will usually react more strongly than bonds and other debt to actual or perceived changes in the company's financial condition or prospects. Preferred securities of smaller companies may be more vulnerable to adverse developments than preferred securities of larger companies.

REIT Investment Risk. Investments in REITs involve unique risks. REITs may have limited financial resources, may trade less frequently and in limited volume, may engage in dilutive offerings of securities and may be more volatile than other securities. REIT issuers may also fail to maintain their exemptions from investment company registration or fail to qualify for the "dividends paid deduction" under the Internal Revenue Code of 1986, as amended, which allows REITs to reduce their corporate taxable income for dividends paid to their shareholders.

Sector Risk. Sector risk is the risk that the Fund's concentration in the

securities of companies in a specific market sector or industry will cause the Fund to be more exposed to the price movements of companies in and developments affecting that sector than a more broadly diversified fund. To the extent that the Fund concentrates its investments in a particular sector, there is the risk that the Fund will perform poorly during a downturn in that sector.

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.

Management

Investment Adviser and Sub-Adviser. The Fund's investment adviser is BFA. The Fund's sub-adviser is BlackRock International Limited ("BIL" or the "Sub-Adviser").

Portfolio Managers. Jonathan Adams and Suzanne Ly, CFA, FRM (the "Portfolio Managers") are jointly and primarily responsible for the day-to-day management of the Fund. Dr. Adams has been a Portfolio Manager of the Fund since March 2021 and Ms. Ly has been a Portfolio Manager of the Fund since August 2022.

Purchase and Sale of Fund Shares

The 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.