What was the name of the abrupt U.S. equity-market plunge on May 6, 2010?

The abrupt U.S. equity-market plunge on May 6, 2010, was called the Flash Crash.

During the afternoon, major U.S. stock indexes dropped rapidly before recovering much of the loss. The Dow Jones Industrial Average briefly fell nearly 1,000 points, an unusually large intraday move for the period.

Investigations linked the event to interactions among high-frequency trading, automated order systems, and a large sell order in an already nervous market. Liquidity temporarily disappeared in parts of the market, causing some securities to trade at extremely distorted prices.

The Flash Crash differed from a conventional multi-month bear market: its most dramatic movement unfolded in minutes. Regulators responded with measures including single-stock circuit breakers and stronger monitoring of automated trading. A later U.S. Justice Department case charged trader Navinder Singh Sarao in connection with spoofing, though the event involved broader market mechanisms.