The severe 1929 Wall Street sell-off that followed Black Thursday was called Black Tuesday.
Black Tuesday occurred on 29 October 1929, when investors traded roughly 16 million shares on the New York Stock Exchange. Prices plunged as panic selling overwhelmed buyers. The Dow Jones Industrial Average fell about 12 percent that day, following a decline of nearly 13 percent on Black Monday, 28 October.
The crash did not by itself create every condition of the Great Depression, but it became its most famous financial symbol. The United States economy was already vulnerable because of excessive speculation, widespread buying on margin, uneven industrial production, and weaknesses in the banking system.
Black Tuesday is often mixed up with Black Thursday, 24 October 1929, when unusually heavy selling first alarmed the public. The two days were part of a wider collapse that continued into 1932, when the Dow reached its low for the period. The crash also helped inspire later securities regulation, including the creation of the U.S. Securities and Exchange Commission in 1934.