What was the May 6, 2010 U.S. market plunge called?

The May 6, 2010 U.S. market plunge was called the Flash Crash.

During the afternoon of May 6, major U.S. stock indexes suddenly dropped and then recovered much of the loss within minutes. The Dow Jones Industrial Average fell almost 1,000 points, one of its largest intraday point declines at that time. Prices in some individual shares and exchange-traded products became extremely distorted.

Investigations concluded that automated trading, market liquidity, and a large sell order interacted in ways that intensified the move. A trader, Navinder Singh Sarao, was later prosecuted in connection with spoofing activity, although the event involved broader market mechanisms as well.

The Flash Crash is different from a conventional bear market because its most dramatic movement occurred within minutes and was followed by a rapid partial recovery.