The sudden U.S. market plunge on May 6, 2010, when the Dow briefly lost almost 1,000 points, is known as the Flash Crash.
During the afternoon session, the Dow Jones Industrial Average fell about 1,000 points, or roughly 9%, in minutes before recovering much of the loss. Many individual securities experienced extreme temporary price moves, including trades at implausibly low or high prices.
Investigations linked the episode to interactions among high-frequency trading, automated orders, market fragmentation, and a large sell order in E-mini S&P 500 futures. The event showed how algorithms could amplify a rapidly changing market, although no single factor fully explains every movement.
U.S. regulators responded with measures including single-stock circuit breakers and later broader limit-up-limit-down rules. The event differs from Black Monday in 1987 because the 2010 decline was extraordinarily rapid and largely reversed the same day. It also differs from a conventional bear market, which develops over a much longer period.