Black Tuesday, the most famous 1929 Wall Street trading day, occurred on October 29, 1929.
On that Tuesday, investors sold millions of shares on the New York Stock Exchange amid collapsing confidence. The Dow Jones Industrial Average fell about 12 percent, following sharp declines on Black Thursday, October 24, and Black Monday, October 28. The episode is remembered as the dramatic climax of the initial crash.
The crash did not by itself cause the entire Great Depression. Other factors included falling industrial output, bank failures, debt problems, reduced international trade, and policy mistakes. The market decline nevertheless damaged household wealth and business confidence, making the economic downturn worse.
A frequent mix-up is treating Black Tuesday as the first day of the crash. October 24 was the first especially chaotic session, while October 29 produced the heaviest early selling. The Dow eventually fell far below its 1929 peak before reaching a low in 1932.