The sudden U.S. stock-market collapse on May 6, 2010, is commonly called the Flash Crash.
During the afternoon of May 6, major U.S. equity indexes plunged rapidly and then recovered much of the loss within minutes. The Dow Jones Industrial Average briefly fell about 1,000 points, or roughly 9%, making the episode one of the most dramatic short-lived market disruptions in modern history.
Investigations found that automated trading played a central role in the extreme movement. A large sell order in an already stressed market interacted with high-frequency trading and liquidity conditions, causing prices in stocks, exchange-traded funds, futures, and options to move violently. The precise mechanisms were complex, and no single ordinary investor action explains the entire event.
The Flash Crash differed from classic crashes such as 1929 or 1987 because its most extreme phase unfolded within minutes and was followed by a substantial rebound. Regulators later introduced or strengthened safeguards, including trading pauses and controls intended to reduce the risk of similar disorderly moves.