How long did the extreme phase of the 2010 United States Flash Crash last?

The extreme phase of the 2010 United States Flash Crash lasted about 36 minutes.

On May 6, 2010, U.S. markets plunged rapidly in the afternoon and then recovered much of the loss. The Dow Jones Industrial Average briefly fell nearly 1,000 points, while many stocks and exchange-traded products traded at wildly abnormal prices. The sharpest moves occurred over roughly 36 minutes.

Investigations described a complex interaction among high-frequency trading, algorithmic orders, market liquidity, and a large sell order in E-mini S&P 500 futures. Trading systems and market structures amplified the initial pressure. Regulators later introduced safeguards, including circuit breakers and rules for handling clearly erroneous trades.

The Flash Crash is not the same as the 1987 Black Monday collapse or the 2015 market turbulence. Its defining feature was extraordinary speed within one trading session, followed by a substantial rebound. The event also showed how modern electronic markets can behave differently from slower, human-dominated markets.