ProShares UltraProShort Nasdaq Biotechnology seeks daily investment results, before fees and expenses, that correspond to three times the inverse (-3x) of the daily performance of the NASDAQ Biotechnology Index.This Short ProShares ETF seeks a return that is -3x the return of an index or other benchmark (target) for a single day, as measured from one NAV calculation to the next. Due to the compounding of daily returns, ProShares returns over periods other than one day will likely differ in amount and possibly direction from the target return for the same period. These effects may be more pronounced in funds with larger or inverse multiples and in funds with volatile benchmarks. Investors should monitor their holdings consistent with their strategies, as frequently as daily.