The 2010 event in which U.S. stocks briefly plunged and then recovered within minutes was the Flash Crash. It occurred on May 6, 2010, during an already volatile period in financial markets.
The Dow Jones Industrial Average fell about 1,000 points, or roughly 9%, during the session before recovering much of the loss. Investigations found that automated trading, market liquidity problems, and a large sell order interacted in a way that intensified the decline.
The Flash Crash differed from a conventional long bear market because its most dramatic movement happened extremely quickly. Some individual securities briefly traded at wildly abnormal prices. Later regulatory changes introduced or strengthened safeguards such as circuit breakers and rules for clearly erroneous trades.