The sudden U.S. stock-market plunge on May 6, 2010, was the Flash Crash.
During the afternoon, major U.S. indexes fell rapidly and then recovered much of the loss within minutes. The Dow Jones Industrial Average temporarily dropped nearly 1,000 points, one of its largest intraday point swings. Many individual securities also traded at extremely low or unusually high prices before normal conditions returned.
Investigations concluded that automated trading and a large sell order contributed to the event. The U.S. Securities and Exchange Commission and the Commodity Futures Trading Commission described interactions among algorithmic trading, liquidity withdrawal, and market stress as important factors. A trader, Navinder Singh Sarao, was later accused and convicted in connection with spoofing-related activity.
The Flash Crash differs from a conventional bear market: it was exceptionally fast and partly reversed the same day. It led to changes including single-stock circuit breakers and stronger monitoring of automated trading.