The S&P 500 reached its closing low during the 2007–2009 stock-market crash on 9 March 2009.
The index closed at 676.53 that day, marking the low point of a bear market that had begun after the S&P 500’s record close in October 2007. The decline reflected the worldwide financial crisis, which involved collapsing housing markets, severe credit problems, bank failures, and recession.
The crisis intensified in September 2008 after the failure of Lehman Brothers, but the stock-market low came several months later. Investors were still absorbing weak economic data, corporate losses, and uncertainty about the effectiveness of government rescue programs.
The date is sometimes confused with the crisis’s most dramatic news events, including Lehman Brothers’ bankruptcy on 15 September 2008. The S&P 500 subsequently began a long recovery, although the economic effects of the crisis continued for years.