The PowerShares Dynamic Oil & Gas Services Portfolio (Fund) is based on the Dynamic Oil & Gas Services IntellidexSM Index (Intellidex Index). The Fund will normally invest at least 90% of its total assets in common stocks that comprise the Index. The Intellidex Index thoroughly evaluates companies based on a variety of investment merit criteria, including: price momentum, earnings momentum, quality, management action, and value. The Underlying Intellidex Index is composed of stocks of 30 U.S. companies that assist in the production, processing and distribution of oil and gas. The Underlying Intellidex Index may include companies that are engaged in the drilling of oil and gas wells; manufacturing oil and gas field machinery and equipment; or providing services to the oil and gas industry, such as well analysis, platform and pipeline engineering and construction, logistics and transportation services, oil and gas well emergency management and geophysical data acquisition and processing. The Fund and the Index are rebalanced and reconstituted quarterly in February, May, August and November.