The stock market crash of October 1929 signaled the end of the "Roaring Twenties" and the beginning of the Great Depression. This was the second day of the big drop, known as "Black Tuesday," which began one day earlier and occupies the next spot on this list. 3.) Oct. 28, 1929 (-38.33, -12.82%)

Barstool Sports owner and internet personality Dave Portnoy mocked President Trump over major losses the stock market took Monday in response to the new sweeping tariffs his administration