Definition of 'Black Thursday'
The name given to Thursday, Oct. 24, 1929, when the Dow Jones Industrial Average plunged 11% at the open in very heavy volume, precipitating the Wall Street crash of 1929 and the subsequent Great Depression of the 1930s.
More recently, "Black Thursday" is also used to refer to the Thanksgiving holiday in the United States, as more retailers open on Thanksgiving evening in a bid to get an early start on the frenzied shopping of Black Friday.
Investopedia explains 'Black Thursday'
Black Thursday and the consequent market crash of 1929 triggered a complete overhaul of market regulation of the U.S. securities industry. These events led to the promulgation of the Securities Act of 1933 and the Securities Exchange Act of 1934.
The shopping version of "Black Thursday" has led to growing resistance among employees of retailers, who complain that they are forced to leave Thanksgiving family dinners early in order to report to work on time. Many retailers are opening earlier on Black Thursday with every passing year in order to counter the increasing popularity of online sales.