The 2010 Flash Crash caused a rapid plunge in U.S. stock indexes on May 6, 2010.
During the afternoon of May 6, major U.S. equity indexes suddenly dropped and then recovered much of the loss within minutes. The Dow Jones Industrial Average briefly fell by nearly 1,000 points, an extraordinary move for such a short period. Some individual securities traded at implausible prices before normal conditions returned.
Investigations by U.S. regulators concluded that a large automated sell order, combined with existing market stress and high-frequency trading behavior, helped trigger and amplify the episode. The precise chain involved interactions among algorithms, liquidity providers, exchanges, and trading rules rather than a single ordinary news announcement.
The event led to reviews of market safeguards, trading access, and price controls. Regulators expanded mechanisms designed to pause or constrain trading when prices move too quickly.
The Flash Crash differs from a conventional bear market. It was exceptionally abrupt and partially reversed the same day, whereas longer crashes unfold across weeks, months, or years.