Buying stocks before U.S. The Standard & Poor’s 500 Index has climbed an average of 2.2 percent in the month before Alcoa Inc. (AA) disclosed results, according to data compiled by Bloomberg since the beginning of the bull market. The S&P 500 traded near a two-month low today as investors weighed corporate results before the Federal Reserve releases minutes from its last meeting. The next month will see a flood of information for investors to sort through, with more than 400 companies in the S&P 500 scheduled to provide a quarterly update.