October 29, 1929, was nicknamed Black Tuesday because U.S. share prices suffered their sharpest major fall of the Wall Street Crash that day.
The Dow Jones Industrial Average fell about 12.8% on October 29, after dropping nearly 13% on Black Monday, October 28. Trading volume reached a then-record level as investors rushed to sell. The collapse followed a long speculative boom in which many buyers used borrowed money to purchase shares.
Black Tuesday did not instantly create the entire Great Depression, and the market continued falling after it. The Dow ultimately reached a low in July 1932, roughly 89% below its September 1929 peak. The crash damaged banks, businesses, and household wealth, while the Depression had additional causes, including debt problems and falling production.
Black Thursday refers to October 24, 1929, the first dramatic selling day in the commonly used sequence of crash nicknames. Black Monday and Black Tuesday followed the next week.