Which 1929 event began with a record 12.9 million shares traded on October 24?

The 1929 Wall Street Crash began its most famous phase with Black Thursday on October 24, 1929.

That day, panic selling produced a record trading volume of about 12.9 million shares on the New York Stock Exchange. A group of major bankers bought shares to support prices, and the market temporarily recovered. The respite did not last: selling intensified again on Black Monday and Black Tuesday.

Black Thursday is often confused with Black Tuesday, October 29, when the Dow Jones Industrial Average suffered another dramatic collapse. The crash followed years of speculative buying, widespread use of borrowed money, and concerns that share prices had risen beyond company earnings.

The crash did not single-handedly cause the Great Depression, but it severely damaged confidence and helped deepen an economic downturn already developing in the United States and elsewhere. The trading volume record set on October 24 was extraordinary for the era and became a lasting symbol of the crisis.