The October 24, 1929 trading day that marked the first major shock of the Wall Street Crash was called Black Thursday.
On that Thursday, panic selling overwhelmed the New York Stock Exchange after a period of rapidly rising share prices and widespread speculation. A group of major bankers bought large blocks of heavily traded stocks to calm the market, and the Dow Jones Industrial Average ended the day down about 6.4% rather than suffering an even steeper collapse.
The temporary rescue did not solve the deeper problems. Investors had bought shares with borrowed money, and many companies and households were exposed to falling asset values. Selling resumed the following week, with Black Monday on October 28 and Black Tuesday on October 29 becoming even more notorious milestones.
The crash did not alone cause the Great Depression, but it intensified a broader economic downturn. Bank failures, declining production, unemployment, and reduced international trade followed during the early 1930s.