The rapid US stock-market collapse on May 6, 2010, became known as the Flash Crash.
During the afternoon of May 6, major US equity indexes plunged and then recovered much of the loss within minutes. The Dow Jones Industrial Average briefly fell about 1,000 points, or approximately 9%, before rebounding. Prices in individual shares and exchange-traded products became unusually distorted.
Investigations found that automated trading, high-frequency trading and a large sell order contributed to the episode's speed and intensity. The US Commodity Futures Trading Commission and Securities and Exchange Commission concluded that a trader's use of an automated execution algorithm helped interact with stressed market conditions, though the event reflected broader market-structure weaknesses.
The Flash Crash demonstrated that modern markets could move extraordinarily fast without a conventional news announcement. It is distinct from Black Monday in 1987, which involved a much larger percentage decline over a full trading day. New circuit breakers and other safeguards were introduced or strengthened afterward.