The Dow Jones Industrial Average lost 22.6 percent on October 19, 1987, the largest single-day percentage decline in its history.
The fall amounted to 508 points, a striking figure at the time. Percentage comparisons are more useful than point comparisons because the Dow’s level changes over decades. For example, a modern point decline can be much larger while representing a smaller share of the index.
The 1987 crash was global rather than confined to Wall Street. Hong Kong, London, and other major markets recorded steep losses around the same period. Analysts have linked the episode to overvalued shares, monetary conditions, international trade tensions, and automated trading strategies, although no single explanation fully accounts for it.
Unlike the 1929 crash, the 1987 decline did not lead directly to a comparable Great Depression. Trading rules, central-bank communication, and market structure were subsequently reviewed, and circuit breakers were introduced or strengthened in several markets.