The 2010 event in which U.S. stocks briefly plunged and rebounded within minutes was the Flash Crash.
On May 6, 2010, major U.S. equity indexes suddenly dropped and then recovered much of the loss. The Dow Jones Industrial Average fell about 1,000 points, or roughly 9%, during the session. Some individual securities traded at extraordinarily low prices before normal conditions returned.
Investigations concluded that automated high-frequency trading and a large sell order interacted with existing market stress and fragmented electronic liquidity. In 2015, U.S. authorities charged trader Navinder Singh Sarao with using spoofing-related activity that contributed to the event, though the crash involved a wider market structure than one simple cause.
The Flash Crash differs from a conventional bear market. It unfolded in minutes and largely reversed the same day, whereas crashes such as 1929 and 2008 involved sustained declines over much longer periods.