The 1987 market crash that began after the Hong Kong stock market fell sharply and spread through global exchanges was Black Monday.
The global episode is dated October 19, 1987, when the Dow Jones Industrial Average plunged 22.6 percent. Heavy selling had already appeared in Hong Kong and other markets, moving westward through time zones. European exchanges then experienced severe losses before the New York session.
The crash reflected several overlapping pressures, including concerns about trade imbalances, currency movements, interest rates, and valuations. Computerized trading strategies, especially portfolio insurance, added automatic selling to an already fragile market and helped accelerate the decline.
Black Monday is sometimes used for other market collapses, including the 1929 event on October 28. In standard financial-history usage, however, “Black Monday” most often refers to the worldwide crash of October 19, 1987. The Dow recovered much of the fall over subsequent trading sessions.