What was the name of the New York Stock Exchange panic day on October 24, 1929?

The New York Stock Exchange panic day on October 24, 1929, was called Black Thursday.

On that day, 12.9 million shares changed hands, setting a trading-volume record at the time. Prices plunged in the morning, and panic selling became so intense that leading bankers met at J.P. Morgan & Co. to coordinate purchases intended to restore confidence.

The intervention produced only temporary relief. Selling returned the following week, especially on October 28 and October 29. October 29 became known as Black Tuesday and is often treated as the most famous single day of the 1929 crash.

Black Thursday is sometimes incorrectly used as a general name for the entire Wall Street Crash. More precisely, it identifies the first major panic day in the sequence. The crash helped usher in the Great Depression, although historians generally describe the depression as having multiple causes rather than a single event.