What nickname was given to the severe U.S. stock-market drop on May 6, 2010?

The severe U.S. stock-market drop on May 6, 2010, was nicknamed the Flash Crash.

During the afternoon of May 6, major U.S. equity indexes plunged rapidly and then recovered much of the loss within minutes. The Dow Jones Industrial Average fell about 1,000 points, or roughly 9%, at the session's low before rebounding.

The event involved high-frequency trading, automated orders, thin liquidity, and a large sell order in an already stressed market. Investigators later concluded that a trader's algorithmic sale of E-mini S&P 500 futures contributed to the episode, while other automated systems amplified the move.

The Flash Crash differed from traditional crashes because its most dramatic movement happened extremely quickly and was partly reversed the same day. The episode led U.S. regulators and exchanges to improve monitoring, create stronger trading controls, and clarify procedures for cancelling clearly erroneous trades. It is not the same event as the 1987 Black Monday crash.