The New York Stock Exchange experienced the largest one-day percentage loss of the 1929 crash on October 28, 1929. The Dow Jones Industrial Average fell 12.82% that day, which became known as Black Monday.
Selling intensified after weeks of anxiety about highly valued shares, speculation on margin, and weakening economic confidence. The following day, October 29, brought another severe decline and became known as Black Tuesday.
The crash did not single-handedly cause the Great Depression, but it damaged businesses, investors, and banks. The depression developed through several interacting forces, including bank failures, debt problems, falling demand, and restrictive economic policies.