During the 1987 Black Monday crash, the Dow Jones Industrial Average fell 508 points on 19 October.
That drop represented a decline of 22.6%, making it the largest one-day percentage fall in the index’s history. The loss was especially striking because the Dow had risen sharply during the preceding years, creating concern that share prices had become detached from economic fundamentals.
The crash was not confined to the United States. Stock markets in Europe, Asia, Australia, and Canada also suffered severe losses, making Black Monday a genuinely global market event. Modern explanations emphasize computerized trading, portfolio insurance, overvalued shares, and international market linkages, although no single cause explains every movement.
The 508-point figure is a point change, not a percentage. Because the Dow’s level has grown substantially since 1987, later crashes have produced much larger point losses while remaining smaller percentage declines.