The investment seeks daily investment results, before fees and expenses, that correspond to two times the inverse (-2x) of the daily performance of the NYSE Arca Gold Miners Index. The fund invests in financial instruments that ProShare Advisors believes, in combination, should produce daily returns consistent with the fund's investment objective. The index is a modified market-capitalization weighted index primarily composed of publicly traded companies involved in the mining for gold and silver. The fund is non-diversified.