Black Tuesday is the name given to the October 29, 1929, sell-off that helped define the Wall Street Crash.
On that Tuesday, about 16 million shares changed hands on the New York Stock Exchange, a record at the time, while the Dow Jones Industrial Average fell roughly 12%. The session followed Black Thursday on October 24 and Black Monday on October 28, making the late-October sequence especially destructive.
The crash followed years of speculative buying, widespread use of borrowed money, and rapidly rising share prices during the 1920s. Falling prices damaged investors, banks, businesses, and households, although the crash itself was one part of the longer economic downturn known as the Great Depression.
A common mix-up is treating Black Tuesday as the entire depression. It refers specifically to October 29, while “Wall Street Crash of 1929” describes the broader market collapse and its surrounding events.