Which US stock index suffered the largest intraday point drop during the 2010 Flash Crash?

The Dow Jones Industrial Average suffered the largest intraday point drop during the 2010 Flash Crash.

On May 6, 2010, the Dow fell about 1,000 points, or roughly 9 percent, within minutes before recovering much of the loss. The extreme movement affected several US equity indexes and many individual securities, with some trades occurring at unusually low prices.

Investigations connected the event to a combination of market conditions, automated trading, and a large sell order. The US Securities and Exchange Commission and the Commodity Futures Trading Commission concluded that a trader’s activity interacted with high-frequency trading and declining liquidity, accelerating the plunge.

The Flash Crash differed from a conventional, sustained bear market: much of the fall and rebound happened during one afternoon. It prompted changes including circuit breakers and tighter controls on exceptionally rapid price movements. The Dow’s point loss is distinct from the percentage losses recorded by the broader market.