The Fund seeks to track the investment results of the S&P 500 Top 20 Select Index, which measures the performance of the 20 largest U.S. companies by float-adjusted market capitalization within the S&P 500 as determined by S&P Dow Jones Indices LLC. The securities in the Underlying Index are weighted based on the float-adjusted market value of their outstanding shares subject to capping. For capping purposes, the Underlying Index will be rebalanced on a quarterly basis. At each quarterly rebalance in March, June, September, and December, the weight of any single issuer will not exceed 22.5% of the Underlying Index; and the aggregate weight of issuers with individual weights exceeding 4.5% will not exceed 48% of the Underlying Index. Between rebalances, constituent weights may exceed these constraints due to fluctuations in market value, corporate actions, or other events that change the index composition. As of August 30, 2024, a significant portion of the Underlying Index is represented by securities of companies in the technology industry or sector. 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. Unlike many investment companies, the Fund does not try to beat the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.