Hong Kong’s severe stock-market collapse in October 1987 was known as Black Monday.
On October 19, 1987, the Hang Seng Index fell 46.1% during a worldwide market panic. The Hong Kong Stock Exchange then closed for several days to allow the market to stabilize. The shock was especially severe because Hong Kong’s market had risen dramatically earlier in the decade and was closely connected to international capital flows.
The same date produced major losses in the United States, the United Kingdom, Australia, and other markets. In New York, the Dow Jones Industrial Average fell 22.6%, its largest one-day percentage decline. The Hong Kong and U.S. figures are often confused because both are central to the story of Black Monday.
The crash prompted reforms to trading systems and market safeguards. Hong Kong’s exchange structure also changed in later years, eventually becoming part of Hong Kong Exchanges and Clearing. The event was not limited to one market; it was a synchronized global financial shock.