Black Monday was the 1987 market crash that began in Hong Kong before spreading rapidly to other global exchanges.
The crash started on October 19, 1987, in Hong Kong and moved westward through international markets. The Dow Jones Industrial Average fell 22.6% that day, while other major markets also suffered exceptionally large losses. Australia, the United Kingdom, and many European markets recorded steep declines during the same episode.
Several factors were involved, including high valuations, concerns about interest rates and exchange rates, portfolio insurance, and program trading. No single explanation accounts for every market’s movement, but computerized trading accelerated selling once the decline began.
The name can be confusing because the U.S. date was Monday, while some Asian markets experienced the first wave on Tuesday, October 20, local time. Black Monday is therefore the standard global name for the event.