Until July 2007, the S&P Preferred Stock Index was characterized by relative stability. Firm values of financial institutions were high and preferred stocks had returns which were similar to bonds. Beginning in the summer of 2007, the volatility of returns in the common stocks of financial firms increased significantly. The S&P Financial Sector Index approximately doubled in volatility in August 2007. After August 2007, the Preferred Stock Index became more correlated with the S&P 500 and the S&P Financial Index and less correlated with.
