The sharp U.S. market collapse on 6 May 2010 is known as the Flash Crash.
During the afternoon, major U.S. equity indexes plunged rapidly before recovering much of the loss within minutes. The Dow Jones Industrial Average briefly fell nearly 1,000 points, or about 9%, its largest intraday point decline at that time.
Investigations found that automated high-frequency trading and a large sell order in E-mini S&P 500 futures contributed to the episode. Liquidity disappeared as computerized systems reacted to rapidly changing conditions, although the event resulted from interacting market mechanisms rather than one simple cause.
The crash led regulators and exchanges to improve safeguards. Measures included circuit breakers, single-stock trading pauses, and stronger monitoring of algorithmic activity. It is distinct from a conventional bear market because its defining feature was the extraordinary speed of the fall and partial recovery.