Which U.S. stock-market crash began on October 19, 1987, in Hong Kong before spreading worldwide?

The 1987 stock-market crash began in Hong Kong before spreading worldwide, culminating in the famous Black Monday session on October 19, 1987. Major markets across Asia, Europe, and North America fell in rapid succession.

Hong Kong’s Hang Seng Index dropped 45.8% between October 19 and October 26. The selling then moved through international markets, and the Dow Jones Industrial Average fell 22.6% on October 19, its largest one-day percentage decline.

The episode differed from 1929 and 2008 because it was not followed by a comparable global depression or banking collapse. Explanations include overvalued shares, rising interest rates, portfolio insurance, and linked international markets. Regulators later introduced or strengthened safeguards such as trading curbs and circuit breakers to slow disorderly selling.