A stock market crash is a sudden dramatic decline of stock prices across a significant cross-section of a stock market, resulting in a significant loss of paper wealth. Crashes are driven by panic as much as by underlying economic factors. They often follow speculative stock market bubbles.
Stock market crashes are social phenomena where external economic events combine with crowd behavior and psychology in a positive feedback loop where selling by some market participants drives more market participants to sell. Generally speaking, crashes usually occur under the following conditions: a prolonged period of rising stock prices and excessive economic optimism, a market where P/E ratios exceed long-term averages, and extensive use of margin debt and leverage by market participants.
There is no numerically specific definition of a stock market crash but the term commonly applies to steep double-digit percentage losses in a stock market index over a period of several days. Crashes are often distinguished from bear markets by panic selling and abrupt, dramatic price declines. Bear markets are periods of declining stock market prices that are measured in months or years. While crashes are often associated with bear markets, they do not necessarily go hand in hand. The crash of 1987, for example, did not lead to a bear market. Likewise, the Japanese Nikkei bear market of the 1990s occurred over several
The 1920's were a time of unbelievable prosperity. The Stock Market was going through the roof and the United States seemed to have the formula for limitless prosperity. However, the same formula that generated all of that profit would also be the cause of Black Tuesday.
Investment during the 1920's was based on the unstable basis of margin buying. Investors bought borrowed money from their brokers, who went to banks for that money. When stocks failed and investors needed to default, the money was permenantly lost.
However, adding to the crash of '29 was the slowing economy. The desire for consumer durables (expensive items refrigerators, radios, and automobiles) went down as Americans became satisfied with what they had. This in turn affected the companies and workers that produced these items. A downward spiral was set in motion.On September 16, 2008, failures of massive financial institutions in the United States, due primarily to exposure of securities of packaged subprime loans and credit default swaps issued to insure these loans and their issuers, rapidly devolved into a global crisis resulting in a number of bank failures in Europe and sharp reductions in the value of equities (stock) and commodities worldwide. The failure of banks in Iceland resulted in a devaluation of the Icelandic Krona and threatened the government with bankruptcy. Iceland was able to secure an emergency loan from the IMF in November. In the United States, 15 banks failed in 2008, while several others were rescued through government intervention or acquisitions by other banks. On October 11, 2008, the head of the International Monetary Fund (IMF) warned that the world financial system was teetering on the "brink of systemic meltdown."
The economic crisis caused countries to temporarily close their markets.
On October 8, the Indonesian stock market halted trading, after a 10% drop in one day.