Which day is associated with the sharpest fall during the 1929 Wall Street Crash?

The day associated with the sharpest fall during the 1929 Wall Street Crash is Black Tuesday.

Black Tuesday was 29 October 1929, when about 16 million shares changed hands on the New York Stock Exchange and the Dow Jones Industrial Average lost roughly 12%. It followed Black Monday, 28 October, when the Dow had already fallen nearly 13%. Together, those sessions intensified the collapse of confidence in U.S. equities.

The crash did not by itself cause every part of the Great Depression. Economic weakness, bank failures, reduced production, debt, and falling demand all helped turn a market collapse into a prolonged worldwide depression. The market had also risen dramatically during the 1920s, encouraging speculation and purchases made with borrowed money. Black Tuesday is sometimes incorrectly treated as the entire crash; the broader Wall Street Crash unfolded over several days and continued afterward.