What was the nickname of the rapid U.S. market plunge on May 6, 2010?

The Flash Crash was the nickname of the rapid U.S. market plunge on May 6, 2010.

During the afternoon of May 6, major U.S. equity indexes fell sharply within minutes before recovering much of the decline. The Dow Jones Industrial Average temporarily lost nearly 1,000 points, at that time its largest intraday point drop. Many individual securities experienced trades at extremely unusual prices.

Investigations found that high-frequency trading and automated order systems played important roles in amplifying the movement. A large sell order in E-mini S&P 500 futures interacted with already strained market conditions and caused liquidity to disappear rapidly. The precise mechanics were complex, and the episode was not simply a conventional wave of human panic.

The event led regulators and exchanges to improve monitoring, strengthen circuit breakers, and introduce mechanisms to cancel clearly erroneous trades. A later U.S. Justice Department case identified trader Navinder Singh Sarao as contributing to the crash through spoofing-related activity, although the broader event involved many interacting systems.