The nickname for October 19, 1987, when global stock markets suffered a historic one-day plunge, was Black Monday.
On that Monday, the Dow Jones Industrial Average fell 508 points, or 22.6%, then the largest one-day percentage decline in its history. Markets in Hong Kong, Europe, Australia, Canada, and other financial centers also dropped sharply, showing how increasingly connected global trading had become.
Several explanations have been studied, including high valuations, trade tensions, rising interest rates, and computerized portfolio-insurance strategies that generated further selling as prices declined. No single cause fully explains the worldwide collapse.
Black Monday is often confused with the 1929 crash’s Black Tuesday, but the dates and market episodes are different. Despite the extreme fall, the 1987 crash did not produce a depression comparable to the 1930s, and the Dow eventually recovered.