The Fund invests in financial instruments that ProShare Advisors believes, in combination, should produce daily returns consistent with the Daily Target. The Index is designed to measure the performance of the 500 largest companies listed and domiciled in the U.S. The top 500 companies based on market capitalization are included in the Index. These companies are then weighted based on market capitalization. The Indexs composition and the assigned weights are reevaluated every September with additional weight adjustments in March, June, and December. The Index is constructed and maintained by S&P Dow Jones Indices LLC.