The 1987 global stock-market crash was called Black Monday after a record one-day fall in Hong Kong helped begin the worldwide sell-off.
Hong Kong’s Hang Seng Index fell sharply on October 19, 1987, before the turmoil moved through European markets and reached the United States. The Dow Jones Industrial Average then dropped 22.6 percent on the same date, the largest one-day percentage decline in its history.
The crash was not caused by one universally accepted event. Concerns about overvalued shares, rising interest rates, trade tensions, and automated portfolio-insurance strategies all contributed to the selling. Program trading amplified the speed of the decline.
Although the name Black Monday is most strongly associated with October 19, 1987, other markets experienced their largest falls on nearby dates because of time-zone differences. The 1987 crash is distinct from Black Monday in 1929, which refers to October 28 of that earlier Wall Street collapse.