During the 2010 Flash Crash, the Dow Jones Industrial Average lost approximately 9.2% intraday.
The event occurred on May 6, 2010, when U.S. equity markets experienced an exceptionally rapid plunge and partial recovery. The Dow fell about 1,000 points, at that time its largest intraday point decline, before recovering much of the loss. Some individual securities briefly traded at extremely low prices.
Investigations identified a complex interaction of factors rather than one simple cause. A large sell order, high-frequency trading, liquidity withdrawal, and automated trading feedback helped intensify the move. The U.S. Securities and Exchange Commission and the Commodity Futures Trading Commission later described how selling pressure moved through markets quickly.
The Flash Crash differed from a conventional bear market because its most dramatic movement unfolded within minutes. Regulators subsequently strengthened trading safeguards, including market-wide circuit breakers and mechanisms for reviewing clearly erroneous trades.