The sudden United States stock-market plunge and recovery on May 6, 2010, is called the Flash Crash.
During the afternoon of May 6, 2010, major U.S. equity indices fell rapidly and then recovered much of the decline within minutes. The Dow Jones Industrial Average briefly lost about 1,000 points, roughly 9 percent, before rebounding. Some individual securities traded at extremely unusual prices during the disruption.
Investigations found that automated trading, high-frequency trading, market liquidity, and a large sell order contributed to the episode. The U.S. Securities and Exchange Commission and Commodity Futures Trading Commission later described how selling pressure moved through interconnected markets. The event was not a conventional multiday bear market like the 1929 crash or the dot-com collapse. It instead highlighted the speed and complexity of modern electronic markets, leading to measures such as single-stock trading pauses and market-wide circuit-breaker reforms.