The investment seeks daily investment results, before fees and expenses, that correspond to the inverse (-1x) of the daily performance of the Dow Jones Industrial AverageSM. The fund invests in derivatives that ProShare Advisors believes, in combination, should have similar daily return characteristics as the inverse (-1x) of the daily return of the index. The index is a price-weighted index maintained by editors of The Wall Street Journal. The index includes 30 large-cap, \"blue-chip\" U.S. stocks, excluding utility and transportation companies. The fund is non-diversified.