The sudden United States market plunge on May 6, 2010, was called the Flash Crash.
During the afternoon, major equity indexes dropped rapidly before recovering much of the loss within minutes. The Dow Jones Industrial Average fell nearly 1,000 points, approximately 9%, during the session. Prices in individual shares and exchange-traded funds became temporarily abnormal, with some trades executing at extremely low or high prices.
Investigations concluded that automated and high-frequency trading interacted with already stressed market conditions. A large sell order in an E-mini S&P 500 futures contract helped create a feedback loop in which algorithms sold into falling prices and liquidity temporarily vanished.
The event was not a conventional multi-year bear market. It was a brief market-structure breakdown, followed by regulatory reviews and new safeguards, including clearer controls for erroneous trades and automatic pauses. The exact contribution of individual traders and systems remained a subject of detailed analysis.