The May 6, 2010, U.S. market plunge was known as the Flash Crash.
During the afternoon of May 6, major U.S. stock indexes fell extremely rapidly. The Dow Jones Industrial Average dropped nearly 1,000 points, or about 9%, before recovering much of the loss within minutes. The episode briefly erased nearly $1 trillion in market value.
Investigations found that automated trading and a large sell order in E-mini S&P 500 futures helped interact with already fragile market conditions. The U.S. Securities and Exchange Commission and the Commodity Futures Trading Commission concluded that the event reflected a complex interaction rather than one simple mechanical error.
The Flash Crash led exchanges and regulators to strengthen market safeguards. Measures included circuit breakers and rules designed to pause trading during unusually rapid price movements. It was a crash in speed and market structure, not a prolonged bear market like 2008.