October 29, 1929, is known as Black Tuesday, the day of a major U.S. stock-market crash.
On Black Tuesday, investors traded roughly 16 million shares on the New York Stock Exchange, an extraordinary volume for the period. The Dow Jones Industrial Average fell about 12%, following heavy losses on the preceding Thursday and Monday.
The crash followed years of speculative buying, widespread use of borrowed money, and rapid expansion in stock prices during the 1920s. Falling confidence caused investors to sell, while margin calls forced many others to liquidate positions.
The crash did not by itself cause every feature of the Great Depression, but it became its most famous financial symbol. Banks failed, unemployment rose, and industrial production contracted during the years that followed. The Dow did not regain its 1929 peak until 1954.