The sudden U.S. market plunge on May 6, 2010, was called the Flash Crash.
During the afternoon of May 6, major U.S. equity indexes dropped rapidly and then recovered much of the loss within minutes. The Dow Jones Industrial Average briefly fell nearly 1,000 points, while some individual securities traded at extremely low prices.
Investigations concluded that a large automated futures transaction, combined with high-frequency trading and stressed market conditions, helped accelerate the fall. A 2015 U.S. Department of Justice case identified trader Navinder Singh Sarao in connection with spoofing-related activity, but the event involved broader market structure issues as well.
The Flash Crash differed from a conventional bear market because its defining feature was extreme speed and partial recovery. It prompted changes to trading safeguards, including tighter circuit breakers and rules for clearly erroneous trades.