The New York Stock Exchange experienced Black Thursday on October 24, 1929.
Black Thursday marked the first major panic day of the Wall Street Crash. Heavy selling drove prices sharply lower after a long period of speculation and rising share values. A group of leading bankers then bought large quantities of prominent stocks in an effort to restore confidence, and prices temporarily stabilized.
The crisis returned with greater force the following week. Black Monday occurred on October 28, followed by Black Tuesday on October 29, when trading volume reached a record for that period and prices fell heavily. The market's decline continued after those famous dates.
A common mix-up is treating October 29 as the beginning of the crash. It was the most famous later panic day, but October 24 was the earlier shock that first exposed the market's instability. The crash contributed to the wider economic collapse of the Great Depression, although it was not its only cause.