The investment seeks daily investment results that correspond to the inverse (-1x) of the daily performance of the Markit iBoxx $ Liquid High Yield Index. 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 modified market-value weighted index designed to provide a balanced representation of U.S. dollar-denominated high yield corporate bonds for sale within the United States by means of including the most liquid high yield corporate bonds available as determined by the index provider. The fund is non-diversified.