The 2010 Flash Crash took about 36 minutes for U.S. markets to lose and largely recover nearly $1 trillion.
On May 6, 2010, U.S. stock indexes fell extremely quickly before recovering much of the decline. The Dow Jones Industrial Average dropped nearly 1,000 points, about 9%, during the session. Some individual securities briefly traded at extraordinarily low prices, while others showed unusual spikes.
Investigations by U.S. regulators found that a large automated sell order, combined with high-frequency trading and stressed market conditions, helped intensify the collapse. The precise interaction among trading algorithms, liquidity withdrawal and order-book dynamics made the episode more complex than a conventional panic.
The crash led to changes including single-stock circuit breakers and improved coordination among exchanges. It is often confused with a normal bear-market day: the defining feature was not simply the size of the loss, but the extraordinary speed of the fall and rebound.