In the 1987 stock-market crash, the Dow Jones Industrial Average fell 22.6% on October 19.
That session, known as Black Monday, was the largest one-day percentage decline in the Dow’s history. The index lost 508 points, closing at 1,738.74. Because the Dow’s level was much lower than in later decades, a loss of 508 points translated into an unusually large percentage move.
Several factors contributed to the panic, including rising interest rates, concerns about the U.S. trade deficit, a weakening dollar, and the rapid expansion of computerized portfolio-insurance trading. Selling spread quickly across international markets, although the economic consequences were less severe than those following the 1929 crash.
The percentage figure is often confused with the point loss. The Dow’s 508-point fall and its 22.6% decline describe the same session in different ways; the percentage is the historically important comparison.