What was the nickname for the U.S. stock-market crash day on October 24, 1929?

The U.S. stock-market crash day on October 24, 1929, was called Black Thursday.

Heavy selling on the New York Stock Exchange drove trading volume to a then-record level. The Dow Jones Industrial Average fell about 11% during the session, although a group of major bankers bought shares near the close and helped limit the decline.

Black Thursday was the first major panic day of the 1929 Wall Street Crash, but it was not the largest percentage fall of that episode. The following week brought Black Monday on October 28 and Black Tuesday on October 29, when selling intensified and the Dow suffered even steeper losses.

The crash did not by itself cause the entire Great Depression. Economic contraction, bank failures, debt problems, falling prices, and policy mistakes deepened the downturn. The nickname is also distinct from Black Thursday in 1929's later market chronology and from unrelated financial events using the same phrase.