Minutes from the Federal Reserve's policy meetings didn't used to gather that much attention.
Released three weeks after each of the eight scheduled meetings of the Federal Open Market Committee, the minutes contain accounts of topics such as foreign currency operations and interest rate policy.
With the Fed now closer to pulling back on its $85 billion a month in bond purchases, investors are looking more closely for clues about how and when the Fed may reduce the program.
The stock market has had several choppy declines this year on previous days that Fed minutes have been released. Here's how the Standard & Poor's 500 index has reacted between the 2 p.m. EDT release of the minutes and the close of trading at 4 p.m., according to Bespoke Investment Group.
— Jan. 3. The S&P 500 retreated from a modest gain and declined 0.4 percent in the last two hours of trading, a moderate decline.
— Feb. 10. The S&P 500 was already down, but fell an additional 0.7 percent after the minutes were released.
— April 10. The S&P 500 was up 1 percent by the time the minutes were released, but then the rally halted. The index edged up just 0.02 percent in the last two hours.
— May 22. After rallying in the morning, the S&P 500 sank 0.8 percent after the minutes were released, a significant move lower.
— July 10. Investors kept their cool this day. The S&P 500 edged up 0.1 percent after the minutes were released. Perhaps investors were more confident that the Fed would only wind down the program once the economy was ready for it.
— Aug. 21. Trading was volatile after the minutes were released. The S&P 500 fell as much as nine points, or 0.6 percent, then rose as much as eight points, or 0.5 percent.
Source: Bespoke Investment Group.