Strategy. The Fund seeks to track the investment results of the S&P Global Clean Energy Transition Index TM (the Underlying Index ), which is designed to track the performance of approximately 100 clean energy-related companies. The Underlying Index is a subset of the S&P Global Broad Market Index and includes stocks traded on developed and emerging market exchanges which meet or exceed, at the time of inclusion, $300 million in total market capitalization, $100 million in float- adjusted market capitalization, and $3 million median daily value traded over a six-month period (or $2 million for existing constituents). S&P Dow Jones Indices LLC (the Index Provider ) uses Global Industry Classification Standard ( GICS ) and FactSets Revere Business Industry Classification System … Show more… The Fund seeks to track the investment results of the S&P Global Clean Energy Transition Index TM (the Underlying Index ), which is designed to track the performance of approximately 100 clean energy-related companies. The Underlying Index is a subset of the S&P Global Broad Market Index and includes stocks traded on developed and emerging market exchanges which meet or exceed, at the time of inclusion, $300 million in total market capitalization, $100 million in float- adjusted market capitalization, and $3 million median daily value traded over a six-month period (or $2 million for existing constituents). S&P Dow Jones Indices LLC (the Index Provider ) uses Global Industry Classification Standard ( GICS ) and FactSets Revere Business Industry Classification System ( RBICS ) classifications along with Trucost Power Generation Data ( Trucost ) for utility companies to determine the eligible universe. Companies that derive at least 25% in aggregate revenue from clean energy related businesses as defined by RBICS data, companies in the Electric Utilities, Multi-Utilities, or Independent Power Producers & Energy Traders sub-industries that generate at least 20% of their power from renewable sources as measured by Trucost data, and companies in the GICS renewable utilities sub-industry form the preliminary universe. In addition, the Index Provider uses company exclusion criteria related to business activity ( e.g. , controversial weapons, tobacco, thermal coal, etc.) and other exclusion guidelines based on a companys compliance with the United Nations Global Compact ( UNGC ) provided by Sustainalytics. Effective with the index review in October 2024, the Index Provider will utilize measurements from S&P Global Business Involvement Screens when monitoring the company exclusion criteria related to business activity (e.g., controversial weapons, tobacco, thermal coal, etc.). Lastly, the Index Provider uses RepRisk, a leading provider of business intelligence on environmental, social, and governance risks, for screening and analysis of controversies related to companies within the index. Companies without coverage are ineligible for index inclusion until they receive such coverage. The Index Provider defines clean energy exposure scores ( exposure scores ) for each company based on its primary business. The Index Provider also calculates carbon-to-revenue footprint standards and excludes those companies with a high carbon-to-revenue footprint standard score determined by the Index Provider. All remaining companies with a high exposure score are selected for the Underlying Index. If the Underlying Index does not have 100 constituents, companies with lower exposure scores are selected, based on market-capitalization, until a constituent count of 100 is reached. If, after a constituent count of 100 is reached, the weighted average exposure score is lower than certain thresholds, companies with low exposure scores will be removed from the Underlying Index. Therefore, while the Underlying Index targets a constituent count of 100 securities, it may be comprised of greater or fewer than 100 securities. As of April 30, 2025, there were 100 constituents in the Underlying Index. Constituents are weighted based on a product of the constituents float-adjusted market capitalization and exposure score, with weights of constituents capped based on their exposure score and liquidity weight. The Index Provider determines liquidity weight based on the relative six-month median daily value of a security compared to that measure for the overall index. In addition, the cumulative weight of all stocks within the Underlying Index that have a weight greater than 4.5% cannot exceed 40%. As of April 30, 2025, the Underlying Index comprised securities of companies in the following countries or regions: Austria, Brazil, Canada, Chile, China, Denmark, Germany, Hong Kong, India, Indonesia, Israel, Italy, Japan, New Zealand, Portugal, South Korea, Spain, Switzerland, Taiwan, Turkey, the United Kingdom ( U.K. ) and the U.S. The Underlying Index may include large-, mid- or small-capitalization companies. As of April 30, 2025, a significant portion of the Underlying Index is represented by securities of companies in the industrials, technology and utilities industries or sectors. The components of the Underlying Index are likely to change over time. BFA uses an indexing approach to try to achieve the Funds investment objective. The Fund does not try to beat the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. Representative sampling is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability and yield) and liquidity measures similar to those of an applicable underlying index. The Fund may or may not hold all of the securities in the Underlying Index. The Fund generally will invest at least 80% of its assets in the component securities of its Underlying Index and in investments that have economic characteristics that are substantially identical to the component securities of its Underlying Index ( i.e ., depositary receipts representing securities of the Underlying Index) and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. Cash and cash equivalent investments associated with a derivative position will be treated as part of that position for the purposes of calculating the percentage of investments included in the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. The Fund may lend securities representing up to one-third of the value of the Fund's total assets (including the value of any collateral received). The Underlying Index is a product of the Index Provider, which is ? independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. Industry Concentration Policy. The Fund will concentrate its investments ( i.e. , hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry. Show less