The May 6, 2010 stock-market plunge was called the Flash Crash.
During the event, major United States equity indexes dropped rapidly and then recovered much of the loss within minutes. The Dow Jones Industrial Average fell about 1,000 points, or roughly 9%, before rebounding. Some individual securities briefly traded at extremely unusual prices.
Investigations linked the episode to a large sell order, algorithmic trading, and a market environment with reduced liquidity. Automated systems interacted in ways that intensified the selling, although the event did not have one simple mechanical cause.
The Flash Crash differed from traditional crashes because its sharpest movement unfolded within a very short period and was followed by a rapid partial recovery. Regulators later introduced measures such as circuit breakers and the limit-up-limit-down system to pause or constrain disorderly trading.