Black Monday was the 1987 crash day when London’s FTSE 100 fell 10.8%.
On October 19, 1987, markets around the world suffered dramatic losses. The FTSE 100 dropped 10.8%, while Hong Kong’s Hang Seng Index fell 46% over the broader crash period and the Dow Jones Industrial Average lost 22.6% in the United States. The shared date and synchronized selling made the episode a landmark in global market history.
The crash developed after a long bull market and amid concerns about interest rates, trade imbalances, economic growth, and stretched valuations. Program trading and portfolio-insurance systems could turn falling prices into additional sell orders, amplifying the decline. Researchers still debate how much each factor contributed.
Black Monday is not the same event as Black Monday in 2020, when global shares plunged during the COVID-19 shock. The 1987 label is also sometimes applied to October 28, 1929, so a date or market should be included when discussing the name.