The 2010 market event in which U.S. stocks plunged and rebounded within minutes because of automated trading was the Flash Crash.
On May 6, 2010, major U.S. equity indexes fell rapidly during afternoon trading. The Dow Jones Industrial Average briefly lost almost 1,000 points, an unusually large intraday move, before recovering much of the decline.
Investigations found that automated trading and the interaction of high-frequency strategies amplified a sharp sell-off. A large sell order in E-mini S&P 500 futures contributed to the pressure, while liquidity providers withdrew or reduced their activity as prices moved quickly.
The crash exposed weaknesses in market structure rather than representing a conventional economic collapse. Regulators introduced measures including circuit breakers and rules intended to pause trading during extreme moves. Some individual securities also recorded trades far outside their normal prices, many of which were later canceled.