Which 2010 event saw U.S. stock indexes plunge rapidly before recovering much of the loss?

The 2010 Flash Crash saw U.S. stock indexes plunge rapidly before recovering much of the loss.

On May 6, 2010, the Dow Jones Industrial Average fell about 1,000 points, roughly 9 percent, in minutes. Many individual securities briefly traded at extremely low prices, although the market recovered a substantial portion of the decline soon afterward.

Investigations by U.S. authorities concluded that a large automated sell order, interacting with high-frequency trading and market conditions, helped trigger and magnify the move. The event exposed weaknesses in fragmented electronic markets and in safeguards designed to halt disorderly trading.

The Flash Crash was not a conventional recession-driven bear market. Its defining feature was speed: prices moved violently within minutes and then partially rebounded. Regulators later introduced or strengthened mechanisms such as single-stock circuit breakers and market-wide trading pauses.