The 1987 international stock-market crash centered on October 19 was called Black Monday.
On that Monday, stock markets around the world fell sharply. The Dow Jones Industrial Average dropped 22.6%, while other major markets recorded even larger percentage declines. Hong Kong’s market fell first among the major exchanges, and selling then spread westward through Asia, Europe, and North America.
The crash followed a substantial multi-year rise in share prices. Concerns about interest rates, currency values, international trade, and market overvaluation combined with computerized trading strategies. Portfolio insurance programs were designed to limit losses but could amplify selling when prices moved downward.
Black Monday did not permanently destroy the financial system. Central banks supplied liquidity, companies continued operating, and market regulations were changed. U.S. exchanges later introduced circuit breakers that temporarily halt trading after large index movements. The name is distinct from Black Monday in 1929, October 28, which occurred during the Wall Street Crash before the 1987 event.