Strategy. The Fund seeks to track the investment results of the Bloomberg US High Yield Fallen Angel 3% Capped Index (the Underlying Index ), which is designed to reflect the performance of U.S. dollar denominated, high yield (as determined by Bloomberg Index Services Limited (the Index Provider or Bloomberg )) corporate bonds that were previously rated investment grade. Bonds are market value weighted with a 3% cap on each issuer. The bonds eligible for inclusion in the Underlying Index are U.S. dollar-denominated corporate bonds that: (i) are issued by companies domiciled in countries classified as developed markets by the Index Provider (based primarily on World Bank income classifications); (ii) have an average rating of below-investment grade (as determined by the Index … Show more… The Fund seeks to track the investment results of the Bloomberg US High Yield Fallen Angel 3% Capped Index (the Underlying Index ), which is designed to reflect the performance of U.S. dollar denominated, high yield (as determined by Bloomberg Index Services Limited (the Index Provider or Bloomberg )) corporate bonds that were previously rated investment grade. Bonds are market value weighted with a 3% cap on each issuer. The bonds eligible for inclusion in the Underlying Index are U.S. dollar-denominated corporate bonds that: (i) are issued by companies domiciled in countries classified as developed markets by the Index Provider (based primarily on World Bank income classifications); (ii) have an average rating of below-investment grade (as determined by the Index Provider); (iii) previously had an average rating of investment grade; (iv) have at least $150 million of outstanding face value; (v) have a fixed-rate coupon; and (vi) have at least one year to maturity. In determining whether a bond has an average rating of investment grade or below-investment grade, ratings from Moodys Investors Services, Inc. ( Moodys ), S&P Global Ratings and Fitch Ratings, Inc. ( Fitch ) are considered. Securities in the Underlying Index must be rated below-investment grade (lower than BBB- by S&P Global Ratings and Fitch, or Baa3 by Moodys) using the middle rating of Moodys, S&P Global Ratings, or Fitch after dropping the highest and lowest available ratings. When a rating from only two agencies is available, the lower more conservative rating is used. When a rating from only one agency is available, that rating is used to determine eligibility in the Underlying Index. If an issue is unrated, the Index Provider may consider expected ratings and/or issuer-level ratings adopted by a ratings agency. There is no limit to the number of issues in the Underlying Index, but as of October 31, 2025, the Underlying Index included approximately 149 constituents. As of October 31, 2025, a significant portion of the Underlying Index is represented by securities of companies in the consumer goods and services and industrials 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 or other instruments that collectively has an investment profile similar to that of an applicable underlying index. The instruments selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration ( i.e. , an instrument's price sensitivity to a change in interest rates), maturity or credit ratings and yield) and liquidity measures similar to those of an applicable underlying index. The Fund may or may not hold all of the components of the Underlying Index. The Fund will invest at least 80% of its assets in the component securities of the Underlying Index, and the Fund will invest at least 90% of its assets in fixed income securities of the types included in the Underlying Index that BFA believes will help the Fund track the Underlying Index. The Fund will invest no more than 10% of its assets in futures, options and swaps contracts that BFA believes will help the Fund track the Underlying Index as well as in fixed income securities other than the types 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 sponsored by Bloomberg, which is ? independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the components of 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), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry. Show less