The investment seeks daily investment results, before fees and expenses, that correspond to two times the inverse (-2x) of the daily performance of the Dow Jones U.S. Basic MaterialsSM Index. The fund invests in derivatives that ProShare Advisors believes, in combination, should have similar daily return characteristics as two times the inverse (-2x) of the daily return of the index. The index measures the performance of the basic materials sector of the U.S. equity market. The fund is non-diversified.