The 2011 market event that followed Standard & Poor’s downgrade of U.S. government debt was called Black Monday.
On August 8, 2011, stock markets around the world fell sharply amid fears about sovereign debt, weak economic growth, and the European debt crisis. Standard & Poor’s had lowered the United States’ long-term credit rating from AAA to AA+ three days earlier, after a prolonged dispute over raising the federal debt ceiling.
The Dow Jones Industrial Average dropped 634.76 points, or 5.55%, on August 8. The decline was especially notable because it came after an already volatile week and occurred across several major markets.
This episode is distinct from Black Monday in 1987 and from the 2010 Flash Crash. “Black Monday” is a recurring label for unusually severe market declines, so the year is essential when identifying the event. The 2011 episode reflected debt and growth concerns rather than a single trading-system malfunction.