What name is commonly given to the severe global stock-market collapse that began in 1929?

The severe global stock-market collapse that began in 1929 is commonly called the Wall Street Crash of 1929.

U.S. share prices had risen dramatically during the 1920s, supported by heavy speculation and widespread use of borrowed money. The market then turned sharply in October 1929. The crash damaged investor confidence and helped deepen the economic contraction that became the Great Depression.

The crash was not the sole cause of the Depression. Bank failures, falling demand, debt, deflation, and policy decisions all contributed to the prolonged downturn. Stock prices also continued falling after October 1929, reaching their low point in 1932.

The Wall Street Crash is often incorrectly treated as a single day. It was a sequence of violent trading sessions and a longer collapse in share values. The event’s most famous trading day has a separate nickname, but that nickname is not the answer here.