Black Tuesday was the name given to 29 October 1929, when U.S. stocks suffered their worst one-day trading loss.
The Dow Jones Industrial Average fell 11.7% that day, closing at 230.07, as roughly 16 million shares changed hands. The selling followed the dramatic declines of Black Thursday on 24 October and Black Monday on 28 October.
Black Tuesday is widely treated as the symbolic climax of the Wall Street Crash of 1929. The crash did not by itself cause the Great Depression, but it severely damaged investor confidence and helped deepen the economic downturn that followed.
A common mix-up is confusing Black Tuesday with Black Thursday. Black Thursday marked the first major wave of panic selling, while Black Tuesday produced the larger percentage loss and became the crash's most famous date. The Dow ultimately fell about 89% from its 1929 peak to its 1932 low.