What was the U.S. stock-market crash of October 24, 1929 commonly called?

The U.S. stock-market crash of October 24, 1929, was commonly called Black Thursday.

Heavy selling hit the New York Stock Exchange that morning, and panic spread as prices fell sharply. A group of major bankers later pooled resources to buy shares and restore confidence, helping the market recover temporarily before the deeper declines of the following week.

Black Thursday was followed by Black Monday on October 28 and Black Tuesday on October 29. Those three labels are sometimes blended together, but they refer to separate trading sessions within the broader Wall Street Crash of 1929.

The market had risen dramatically during the 1920s, supported by widespread optimism and substantial buying on margin. Margin allowed investors to purchase shares with borrowed money, increasing both potential gains and losses. Once prices dropped, investors faced demands for more cash and were often forced to sell, adding pressure to the decline.