The 1929 U.S. stock-market crash day on October 29 was called Black Tuesday.
Black Tuesday followed several days of panic selling on the New York Stock Exchange. Trading volume reached a then-record level, and the Dow Jones Industrial Average fell about 12% that day. The crash did not single-handedly create the Great Depression, but it became its most famous financial symbol.
The collapse followed years of speculative buying, widespread use of borrowed money, and increasingly optimistic expectations about share prices. Banks, businesses, and households were exposed when prices reversed. The downturn then spread through reduced investment, falling production, bank failures, and unemployment.
A common mix-up is Black Thursday, October 24, when an earlier major sell-off occurred, and Black Monday, October 28, when the Dow suffered another severe decline. Together, these sessions formed the dramatic opening phase of the Wall Street Crash.