The Dow Jones Industrial Average dropped about 9 percent during the 2010 Flash Crash.
On May 6, 2010, U.S. equity markets experienced an exceptionally rapid plunge and partial recovery. The Dow lost about 1,000 points, nearly 9 percent, within minutes. Many individual securities and exchange-traded products showed extraordinarily low temporary prices before recovering.
Investigations found that automated trading played an important role. A large sell order in E-mini S&P 500 futures interacted with existing algorithmic activity and reduced market liquidity. The precise episode involved several market mechanisms rather than one simple human decision.
The Flash Crash differed from a conventional bear market because its most dramatic movement occurred in minutes and much of the decline was recovered the same day. Regulators subsequently strengthened circuit breakers and other safeguards for extreme volatility.