The 1929 trading day known as Black Tuesday because of massive Wall Street selling was October 29, 1929.
On Black Tuesday, investors sold millions of shares on the New York Stock Exchange. Prices fell sharply, and panic selling intensified the market collapse that had begun the previous week. The Dow Jones Industrial Average dropped about 12 percent that day.
Black Tuesday followed Black Thursday on October 24 and Black Monday on October 28. These labels describe especially dramatic sessions during the wider Wall Street Crash, rather than separate economic crises.
The stock-market collapse did not by itself create every condition of the Great Depression. Bank failures, reduced spending, debt, declining production, and policy responses also shaped the severe worldwide downturn that followed. Still, Black Tuesday became the crash’s most famous single trading day.