How long did the most dramatic phase of the 2010 United States flash crash last?

The most dramatic phase of the 2010 United States flash crash lasted about 36 minutes.

On May 6, 2010, major U.S. stock indexes plunged rapidly during the afternoon before recovering much of the loss. The Dow Jones Industrial Average temporarily dropped nearly 1,000 points, one of its largest intraday point declines at that time.

Investigations linked the event to a combination of high-frequency trading, computerized orders, market fragmentation, and a large sell order. A 2015 U.S. federal case later charged trader Navinder Singh Sarao with contributing to the crash through spoofing, though the episode involved wider market conditions and systems.

The event showed how quickly automated trading could amplify instability. Regulators subsequently introduced measures such as single-stock circuit breakers and market-wide trading safeguards. The crash is distinct from a conventional, multi-day bear market.