The U.S. stock-market crash that began on October 19, 1987, was called Black Monday.
On that date, the Dow Jones Industrial Average lost 22.6%, its largest one-day percentage decline. The crash followed substantial falls in markets around the world and became one of the most important modern examples of a sudden, broad equity sell-off.
Several factors were associated with the event, including high valuations, concerns about interest rates and trade deficits, program trading, and portfolio-insurance strategies. Selling fed on itself as computerized systems generated additional sell orders in falling markets.
Black Monday is sometimes confused with Black Tuesday, the climactic day of the 1929 Wall Street Crash. The names describe different crashes separated by 58 years, and Black Monday’s percentage loss remains larger than the comparable 1929 daily declines.