This excerpt taken from the PCG 10-K filed Feb 24, 2009.
SRSP Large Company Stock Index Fund seeks to match the performance of the S&P 500 Index. The Fund invests in all 500 stocks in the S&P 500 Index in proportion to their weightings in the Index. The S&P 500 provides exposure to about 85% of the market value of all publicly traded common stocks in the United States. The strategy of investing in the same stocks as the S&P 500 Index minimizes the need for trading and results in lower expenses. The Fund is managed by State Street Global Advisors (SSgA).