Black Thursday was October 24, 1929, the first major panic-selling day of the Wall Street Crash of 1929.
The Dow Jones Industrial Average fell sharply that day as trading volume reached a then-record level. A group of major bankers later attempted to steady prices by buying leading stocks, temporarily calming the market. The intervention did not end the wider collapse.
Black Thursday is often confused with Black Monday and Black Tuesday, which followed on October 28 and October 29. The crash unfolded over several trading sessions rather than on one isolated day.
The 1929 crash followed years of heavy speculation, widespread margin buying, and rising share prices. Its aftermath contributed to the severe economic contraction that became the Great Depression, although historians distinguish the market crash from the broader depression.