Most of the time financial markets run smoothly. Winners usually outnumber losers otherwise no one would invest in the stock exchanges, but it is the dramatically bad times that most people remember. Over the last century, there have been several disastrous periods for Wall Street where the value of stocks as measured by the Dow Jones industrial Average (DJIA) has plummeted more than 40 percent from high to low.

While these dramatic market downturns all occurred over a period of months or years, most are remembered for the one day on which the bottom really fell out of the market. These days are referred to as "black" days, and the terms "Black Monday" or "Black Tuesday" or even "Black Thursday" recall dark days to the minds for market insiders. It also is noteworthy that most of these market crashes began in the months from September to October, perhaps bringing a new meaning to the "fall" season.

Black Tuesday

If not the worst market crash of all time, October 29, 1929, is credited with being the beginning of the Great Depression and is referred to as Black Tuesday. On Black Tuesday a record at the time of 16.4 million shares were traded and the market lost approximately 12 percent of its value. The panic was exacerbated because the volume of trading caused the ticker tape machines tracking stock prices to fall behind by two and a half hours.

Overall, the market crash lasted for 71 days beginning with the DJIA at a high of 381.17 in early September 1929 until it hit bottom in mid-November with the Dow an anemic 198.69. Over a two-month period, investors lost nearly half their money. It is rated as the fourth worst market crash of the 20th century but was not the only one to hit during the Depression.

The Worst Ever

The worst ever crash of the stock market occurred from 1930-1932 and finished off what was left of the American economy not devastated by the Black Tuesday crash. This crash saw the market lose 86 percent of its value. Combined with top-10 crashes in 1937 and 1939, the market did not recover fully until 22 years later in 1954. An investor who had $1,000 in the market in 1929 would have seen that position drop to a worth of only $108 by mid-1932 when the worst of the crashes bottomed out.