The 24 October 1929 US market plunge at the start of the Wall Street crash is known as Black Thursday.
On that Thursday, heavy selling hit the New York Stock Exchange and trading volume reached a record at the time. A group of major bankers attempted to restore confidence by buying selected shares, but the intervention could not prevent further turmoil during the following week.
The crash continued with Black Monday on 28 October and Black Tuesday on 29 October. The collapse did not by itself cause every feature of the Great Depression, but it intensified financial distress and damaged confidence. Bank failures, falling demand, deflation, and policy choices also shaped the depression that followed.
Black Thursday is often mistaken for the single date of the 1929 crash. It was the first major panic day in the famous sequence, while Black Tuesday is usually identified as the most devastating day by total points lost.