What 1929 crash day saw the Dow Jones Industrial Average fall 11.7% on 24 October?

The 1929 crash day when the Dow Jones Industrial Average fell 11.7 percent on 24 October was Black Thursday.

Black Thursday marked the first major panic day of the Wall Street Crash of 1929. Trading volume reached a then-record level as investors rushed to sell shares. A group of major bankers, including Richard Whitney of the New York Stock Exchange, attempted to restore confidence by buying heavily traded stocks, but the broader crisis continued.

The market rebounded temporarily on the following Friday and Saturday before another severe decline on 28 October, known as Black Monday. On 29 October, Black Tuesday, the Dow fell about 12.8 percent. These days formed part of a larger collapse that continued until the market reached its low in July 1932.

Black Thursday is often confused with Black Tuesday because both are associated with the same crash. The crash itself did not single-handedly cause the Great Depression, but it weakened confidence and interacted with banking failures, debt, deflation, and falling production.