The 2010 Flash Crash occurred on May 6, 2010, when U.S. stock indexes plunged and quickly rebounded.
During the afternoon, the Dow Jones Industrial Average fell about 1,000 points, losing roughly 9% within minutes before recovering much of the decline. Some individual securities briefly traded at extremely low prices, while others experienced unusually large swings. The episode exposed how automated trading systems could interact in unstable ways during a fast-moving market.
A joint investigation by the U.S. Commodity Futures Trading Commission and Securities and Exchange Commission concluded that a large automated futures trade, combined with existing market stress and high-frequency trading activity, helped produce the extreme movement. The event was not a conventional multi-year market crash like 1929 or 2008.
The Flash Crash led to reforms including market-wide circuit breakers and mechanisms for reviewing and cancelling clearly erroneous trades. It is also distinct from the separate August 24, 2015, flash crash involving sharp early trading volatility.