What was the name of the U.S. stock exchange panic that began on October 24, 1929?

The U.S. stock exchange panic that began on October 24, 1929, was called Black Thursday.

On that day, heavy selling struck the New York Stock Exchange after weeks of market weakness. A group of leading bankers bought large quantities of blue-chip shares in an attempt to restore confidence, and prices temporarily stabilized. The intervention did not end the wider collapse.

The crash continued through Black Monday on October 28 and Black Tuesday on October 29. Black Tuesday is often treated as the most famous day of the crash, but the events formed part of a longer decline that began after the market peak in September.

The crash helped usher in the Great Depression, although historians distinguish the market collapse from the many economic causes of the Depression. The episode is also frequently confused with the separate Black Thursday market panic of 1907 in Australia.