On "Black Thursday", the New York Stock Exchange lost 11 percent of its value at the opening bell on very heavy trading, marking the beginning of the Great Depression.

The Wall Street crash of 1929, also known as the Great Crash, was a major stock market crash in the United States which began in October 1929 with a sharp decline in prices on the New York Stock Exchange (NYSE). It triggered a rapid erosion of confidence in the U.S. banking system and marked what would later cascade into the worldwide Great Depression that lasted until the United States entered into World War II on December 8, 1941, making it the most devastating crash in the country's history. It is most associated with October 24, 1929, known as "Black Thursday", when a record 12.9 million shares were traded on the exchange, and October 29, 1929, or "Black Tuesday", when some 16.4 million shares were traded.