The Dow Jones Industrial Average fell about 9% during the 2010 Flash Crash.
On May 6, 2010, major U.S. stock indexes plunged rapidly and then recovered much of the loss within minutes. The Dow dropped about 1,000 points, equivalent to roughly 9 percent, before rebounding. Individual securities experienced even more extreme temporary price movements.
Investigations linked the event to an interaction between high-frequency trading, automated orders, and a large sell order in the futures market. The speed of trading allowed liquidity to disappear in some markets, magnifying the decline.
The Flash Crash differed from a traditional bear market. It unfolded within a single trading session rather than through months of sustained deterioration. Regulators later introduced safeguards including circuit breakers and rules intended to address clearly erroneous trades. The event remains an important example of how computerized market structure can accelerate a shock.