What was the nickname of the October 24, 1929 Wall Street sell-off?

The October 24, 1929 Wall Street sell-off was nicknamed Black Thursday.

On that Thursday, panic selling overwhelmed the New York Stock Exchange and trading volume reached a then-record level. The Dow Jones Industrial Average fell nearly 12% from its previous close before major bankers bought heavily traded shares and helped stabilize prices late in the session. The intervention temporarily reassured investors, but it did not end the market’s underlying weakness.

Black Thursday is part of a sequence of famous crash labels. Black Monday followed on October 28, and Black Tuesday came on October 29, when selling and volume became even more extreme. The labels can cause confusion because some accounts use “Wall Street Crash of 1929” for the entire episode rather than a single day. The stock collapse was followed by years of economic distress, although historians generally identify multiple causes for the Great Depression.