The October 1987 day when stock markets around the world suffered their sharpest synchronized fall was nicknamed Black Monday.
Black Monday was October 19, 1987. The Dow Jones Industrial Average fell 22.6%, and major markets in Europe, Asia, and the Pacific also recorded severe losses. The synchronized nature of the decline made it a global market event rather than an isolated U.S. sell-off.
Several pressures contributed, including high valuations, concerns about interest rates and trade imbalances, and selling programs that automatically hedged portfolios. No single explanation accounts for every market’s movement. The crash led exchanges and regulators to develop circuit breakers, which can pause trading during unusually large moves. The nickname is easy to confuse with Black Monday in 1929, but the 1987 event is the one associated with the 22.6% Dow percentage loss.