The 2011 crash: The sovereign debt crisis
Black Monday 2011 refers to Aug. 8, 2011, when U.S. and global stock markets crashed following the Friday night credit rating downgrade by Standard and Poor's of the United States sovereign debt from AAA, or "risk free," to AA+. It was the first time in history the United States was downgraded. Moody's issued a report during morning trading, which said its AAA rating of U.S. credit was in jeopardy, this after issuing a negative outlook in the previous week.
By market close, the Dow Jones Industrial Average lost 634.76 points (-5.55%) to close at 10,809.85, making it the 6th largest drop of the index in history. Black Monday 2011 followed just one trading day behind the 10th largest drop of the Dow Jones Index, a 512.76 (-4.31%) drop on August 4, 2011.