The 6 May 2010 U.S. stock-market plunge and rapid rebound was called the Flash Crash.
During the afternoon of 6 May, major U.S. equity indexes dropped abruptly, with the Dow Jones Industrial Average losing about 1,000 points within minutes before recovering much of the fall. Some individual securities traded at extremely low prices, while liquidity briefly deteriorated across markets.
Investigations found that automated trading, market fragmentation and rapidly changing liquidity interacted in a destabilizing way. The U.S. Securities and Exchange Commission and Commodity Futures Trading Commission concluded that a large sell order in E-mini S&P 500 futures helped initiate the episode, while high-frequency traders amplified the movement.
The crash led to reforms including circuit breakers and safeguards for clearly erroneous trades. It is different from a conventional bear market: the most striking feature was the extraordinary speed of the fall and recovery within a single trading session.