The 2010 market event that caused a brief, extraordinarily rapid U.S. stock sell-off was the Flash Crash.
On May 6, 2010, major U.S. stock indexes plunged and then recovered much of the decline within minutes. The Dow Jones Industrial Average fell about 1,000 points, nearly 9%, before rebounding. Some individual securities briefly traded at extremely low or high prices, creating extraordinary volatility across stocks, futures, and exchange-traded products.
Investigations by U.S. regulators concluded that a large automated sell order in the E-mini S&P 500 futures market interacted with high-frequency trading and stressed market liquidity. The event was not a conventional multi-month bear market like 2008. It demonstrated how computerized trading could amplify a temporary imbalance and led to new controls, including clearer rules for handling erroneous trades and market-wide circuit breakers. The name refers to the speed and suddenness of the collapse.