During the 1987 Black Monday crash, which U.S. stock index fell 22.6% in one day?

During the 1987 Black Monday crash, the Dow Jones Industrial Average fell 22.6% in one day.

The collapse occurred on Monday, October 19, 1987, when stock markets around the world plunged. The Dow’s fall was its largest one-day percentage decline in history, exceeding the losses recorded during the Wall Street Crash of 1929. The decline followed sharp market weakness earlier in October and intensified through automated and portfolio-insurance selling.

The Dow Jones Industrial Average tracks 30 major U.S. companies and is commonly called the Dow. It is a price-weighted index, so companies with higher share prices have more influence on its point movements. The 22.6% figure refers to the index’s percentage loss, not a 22.6% fall in every company’s shares.

Black Monday is sometimes confused with other market events using the same nickname, including the 1929 and 2020 sell-offs. In the 1987 episode, markets in several countries fell sharply, but the Dow’s record percentage decline remains the best-known statistic.