The Flash Crash caused a brief but dramatic U.S. stock-market plunge of nearly 1,000 Dow points on May 6, 2010.
During the afternoon session, the Dow Jones Industrial Average fell about 1,000 points, or roughly 9%, within minutes before recovering much of the loss. Many individual securities experienced unusually extreme prices, and trading conditions became highly unstable.
Investigations concluded that automated high-frequency trading and a large sale of E-mini S&P 500 futures contributed to the event. The U.S. Securities and Exchange Commission and Commodity Futures Trading Commission later described a complex interaction between selling pressure, algorithms, and reduced market liquidity. The event differs from a conventional crash because much of the decline was reversed within the same day.