The sudden collapse and rebound in U.S. share prices on May 6, 2010, was called the Flash Crash.
The Dow Jones Industrial Average briefly lost nearly 1,000 points, about 9%, within minutes before recovering much of the decline. Some individual securities traded at extremely low prices, while major indexes experienced extraordinary intraday volatility.
Investigations by U.S. regulators concluded that a large automated futures sale, combined with high-frequency trading and fragmented liquidity, helped amplify the move. A later U.S. Justice Department case identified trader Navinder Singh Sarao’s spoofing activity as one contributing factor, but the event reflected several interacting market-structure weaknesses.
The Flash Crash differs from a conventional bear market because most of the fall and rebound happened during one trading session. It also differs from Black Monday in 1987, which produced a lasting daily close decline rather than a rapid V-shaped reversal.