ProShares Short MidCap400 (the Fund) seeks daily investment results that correspond to the inverse (opposite) of the daily performance of the S&P MidCap 400 Index (the Index). The S&P MidCap 400 Index is a measure of mid-size company United States stock market performance. It is a capitalization weighted index of 400 United States operating companies and real estate investment trusts (REITs). The Fund intends to invest at least 80% of its net assets, including any borrowings for investment purposes, to investments that, in combination, have economic characteristics that are inverse to those of the Index. The Fund also intends to invest assets not invested in financial instruments, in debt instruments and/or money market instruments. The Fund intends to concentrate its investments in a particular industry or group of industries to approximately the same extent as the Index is so concentrated. ProShare Advisors LLC serves as the investment advisor to the Fund.