Which 1987 market crash began after a sharp fall in Hong Kong’s stock market?

Black Monday was the 1987 market crash that followed a sharp fall in Hong Kong’s stock market and spread through international markets.

Hong Kong’s Hang Seng Index fell sharply in October 1987, and selling then moved through other Asian and European exchanges before reaching the United States. On October 19, the Dow Jones Industrial Average fell 22.6 percent, while markets in many countries recorded severe losses. The synchronized decline made the event a defining example of global financial contagion.

The crash had several interacting causes rather than one universally accepted trigger. Investors faced high valuations, rising interest rates, currency tensions, and concerns about trade. Program trading and portfolio-insurance strategies also increased selling pressure once prices moved lower.

Black Monday is an ambiguous label because it has been used for several crashes. In this context it means October 19, 1987, not October 28, 1929, or March 9, 2020. The 1987 episode led regulators to create mechanisms that could temporarily halt trading during extreme market moves.