The Fund invests in financial instruments that ProShare Advisors believes, in combination, should track the performance of the Index. The Index is designed to measure the performance of the 21 securities from the Nasdaq-100 Index with the highest momentum. The Nasdaq-100 Index is designed to measure the performance of 100 of the largest non-financial companies listed on the Nasdaq Global Select Market or the Nasdaq Global Market (which include both U.S. and non-U.S. companies). The index provider ranks each company in the Nasdaq-100 Index based on relative performance using its proprietary Relative Strength momentum measure. The 21 companies with the highest Relative Strength are selected. These companies are equally weighted in the Index. The Indexs composition is reevaluated and the weightings are reset to equal weight each quarter in January, April, July and October. The Index is constructed and maintained by Dorsey, Wright & Associates, LLC.