The following day, Black Tuesday, was a day of chaos. Forced to liquidate their stocks because of margin calls, overextended investors flooded the exchange with sell orders. The Dow fell 30.57 points to close at 230.07 on that day. The glamour stocks of the age saw their values plummet. Across the two days, the Dow Jones Industrial Average fell 23%.
Markets can also be stabilized by large entities purchasing massive quantities of stocks, essentially setting an example for individual traders and curbing panic selling. However, these methods are not only unproven, they may not be effective. In one famous example, the Panic of 1907, a 50 percent drop in stocks in New York set off a financial panic that threatened to bring down the financial system. J. P. Morgan, the famous financier and investor, convinced New York bankers to step in and use their personal and institutional capital to shore up markets.
On September 16, 2008, failures of massive financial institutions in the United States, due primarily to exposure to packaged subprime loans and credit default swaps issued to insure these loans and their issuers, rapidly devolved into a global crisis. This resulted in a number of bank failures in Europe and sharp reductions in the value of stocks and commodities worldwide. The failure of banks in Iceland resulted in a devaluation of the Icelandic króna and threatened the government with bankruptcy. Iceland obtained an emergency loan from the International Monetary Fund 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 mathematical description of stock market movements has been a subject of intense interest. The conventional assumption has been that stock markets behave according to a random log-normal distribution. Among others, mathematician Benoît Mandelbrot suggested as early as 1963 that the statistics prove this assumption incorrect. Mandelbrot observed that large movements in prices (i.e. crashes) are much more common than would be predicted from a log-normal distribution. Mandelbrot and others suggested that the nature of market moves is generally much better explained using non-linear analysis and concepts of chaos theory. This has been expressed in non-mathematical terms by George Soros in his discussions of what he calls reflexivity of markets and their non-linear movement. George Soros said in late October 1987, 'Mr. Robert Prechter's reversal proved to be the crack that started the avalanche'.
On October 24, many of the world's stock exchanges experienced the worst declines in their history, with drops of around 10% in most indices. In the US, the DJIA fell 3.6%, i.e. not as much as other markets. Instead, both the US dollar and Japanese yen soared against other major currencies, particularly the British pound and Canadian dollar, as world investors sought safe havens. Later that day, the deputy governor of the Bank of England, Charles Bean, suggested that "This is a once in a lifetime crisis, and possibly the largest financial crisis of its kind in human history."
Thirty-two percent of Americans who were invested in the stock market during at least one of the last five financial downturns pulled some or all of their money out of the market. That’s according to a NerdWallet-commissioned survey, which was conducted online by The Harris Poll of more than 2,000 U.S. adults, among whom over 700 were invested in the stock market during at least one of the past five financial downturns, in June 2018. The survey also found that 28% of Americans would not keep their money in the stock market if there were a crash today.
Even they know that the markets go through cycles. And right now, the markets are volatile. 2018 was a roller coaster ride that ended with a minor crash. The S&P 500 ended the year 6.5% in the red and the Nasdaq ended the year down 4.3%. Moreover, it was the worst December to hit Wall Street since the Great Depression, with tech stocks ending a nine-year winning streak.
Having been suspended for three successive trading days (October 9, 10, and 13), the Icelandic stock market reopened on 14 October, with the main index, the OMX Iceland 15, closing at 678.4, which was about 77% lower than the 3,004.6 at the close on October 8. This reflected that the value of the three big banks, which had formed 73.2% of the value of the OMX Iceland 15, had been set to zero.