Here are five of the worst stock market crashes in U.S. history, based on daily percentage losses:
Oct. 19, 1987
Percentage change: -22.61 percent
About: Known as "Black Monday," this devastating crash began in Hong Kong, spread to Europe and then hit the U.S. hard.
Oct. 28, 1929
Percentage change: -12.82 percent
About the crash: The Wall Street Crash of 1929, also known as the Great Crash or the Stock Market Crash of 1929 started on Oct. 24 and signaled the beginning of the 12-year Great Depression. Black Monday, the fourth and worst day of the crash, saw a drop of 12.82 percent.
Dec. 18, 1899
Percentage change: -11.99 percent
About the crash: During the Panic of 1896, the U.S. experienced an acute economic depression caused by a drop in silver reserves and deflation.
Oct. 29, 1929
Percentage change: -11.73
About the crash: Black Tuesday was the fifth day of the the Wall Street Crash of 1929, also known as the Great Crash or the Stock Market Crash of 1929 that started on Oct. 24 and signaled the beginning of the 12-year Great Depression.
Nov. 6, 1929
Percentage change: -9.92
About the crash: Just a week after the height of the 1929 Stock Market Crash, investors saw another dip.
The Associated Press contributed to this story.