The PowerShares S&P 500 Low Volatility Portfolio (Fund) is based on the S&P 500 Low Volatility Index (Index). The Fund will invest at least 90% of its total assets in common stocks that comprise the Index. The Index is compiled, maintained and calculated by Standard & Poor's and consists of the 100 stocks from the S&P 500 Index with the lowest realized volatility over the past 12 months. Volatility is a statistical measurement of the magnitude of up and down asset price fluctuations over time. The Fund and the Index are rebalanced and reconstituted quarterly in February, May, August and November.