On what date did the 1987 Black Monday crash send the Dow Jones Industrial Average down 22.6%?

The 1987 Black Monday crash occurred on October 19, 1987, when the Dow Jones Industrial Average fell 22.6% in one trading session.

The decline was the largest one-day percentage drop in the Dow’s history. Selling spread rapidly through connected international markets, including Hong Kong, London, and Australia. The crash followed a sharp rise in share prices earlier in the decade and growing concern about interest rates, trade deficits, and overvalued markets.

Computerized portfolio-insurance strategies amplified the selling. These systems were designed to reduce losses by selling futures as prices fell, but widespread automatic selling increased downward pressure. The precise cause remains debated, because several financial and economic factors converged.

Black Monday is sometimes confused with the October 1929 crash dates. It was not the start of the Great Depression, and the U.S. economy did not enter a depression after 1987. The Dow recovered much of its loss relatively quickly, helped by coordinated action from central banks and regulators.