What was the popular name for the stock-market plunge on October 19, 1987?

The popular name for the stock-market plunge on October 19, 1987, was Black Monday.

Black Monday is especially associated with the New York Stock Exchange, where the Dow Jones Industrial Average fell 22.6% in one session. That percentage decline remains the largest single-day fall in the Dow’s history. The crash was global: markets in Europe, Asia and other financial centers also recorded sharp losses around the same period.

The name follows a convention used for memorable market disasters, including Black Tuesday in 1929. It refers to the day of the week rather than a particular company or financial product. Because the date was a Monday in the United States, it is distinct from the October 28, 1929, Black Monday.

The 1987 crash prompted regulators and exchanges to reconsider market safeguards. Circuit breakers were introduced or strengthened to pause trading after unusually large movements. These controls are designed to slow panic and give participants time to assess information, although they cannot eliminate market risk.