Which Tuesday in 1929 became the defining day of the Wall Street Crash?

Black Tuesday was the defining day of the 1929 Wall Street Crash, occurring on October 29, 1929.

On that day, about 16 million shares changed hands on the New York Stock Exchange, a record at the time. The Dow Jones Industrial Average fell roughly 12 percent, extending the collapse that had begun with heavy selling on Black Thursday, October 24, and intensified on Black Monday, October 28.

The crash followed years of speculation and widespread buying with borrowed money. Share prices had risen rapidly during the 1920s, while margin investors were vulnerable to demands for additional cash. Once confidence broke, forced selling and fear reinforced one another.

The crash did not single-handedly cause the Great Depression, but it became its most famous financial symbol. Bank failures, falling production, debt problems, reduced investment, and international economic weakness deepened the downturn. Black Tuesday is therefore a date, not the name of the entire multi-day or multi-year crisis.