The 2010 U.S. stock-market plunge caused by extreme automated trading was nicknamed the Flash Crash.
On May 6, 2010, major U.S. indexes fell rapidly before recovering much of the decline within minutes. The Dow Jones Industrial Average briefly lost nearly 1,000 points, while prices in individual stocks and exchange-traded products became highly distorted.
Investigations found that high-frequency trading and a large automated sell order interacted with already tense market conditions and fragmented trading venues. Liquidity temporarily disappeared in some securities, meaning that normal buyers were not available at expected prices.
The event did not resemble a traditional multi-month bear market or a banking collapse. It was a sudden market-structure shock. Regulators later introduced or strengthened tools such as circuit breakers, which pause trading after unusually large price movements. The Flash Crash is also distinct from the 1987 Black Monday crash, which involved a much broader one-day collapse and different market conditions.