The PowerShares S&P 500 ex- Rate Sensitive Low Volatility Portfolio (Fund) is based on the S&P 500 Low Volatility Rate Response Index (Index). The Fund generally will invest at least 90% of its total assets in common stocks that comprise the Index. The Index is composed of the 100 constituents of S&P 500 Index that exhibit both low volatility and low interest rate risk. The Underlying Index is designed to include stocks exhibiting low volatility characteristics, after removing stocks that historically have performed poorly in rising interest rate environments. The Fund and Index constituents are rebalanced and reconstitutioned after the close on the third Friday of February, May, August and November. Constituents are weighted relative to the inverse of their volatility, with the least volatile stocks receiving the highest weights.