The 2010 event when U.S. markets plunged and rebounded within minutes was the Flash Crash.
On May 6, 2010, major U.S. stock indexes fell rapidly before recovering much of the decline. The Dow Jones Industrial Average temporarily dropped nearly 1,000 points, while some individual securities traded at extremely unusual prices.
Investigations linked the episode to a combination of market conditions, automated trading, and a large sell order. A trader, Navinder Singh Sarao, was later accused and convicted in connection with spoofing activity that contributed to the conditions surrounding the crash, though the event also reflected broader structural vulnerabilities.
The Flash Crash encouraged exchanges and regulators to introduce stronger circuit breakers and other safeguards. It differs from a traditional bear market because the sharpest movement occurred over minutes rather than months or years.