Fears about the global economy led to the biggest panic in financial markets since the 2008 financial crisis. The Dow plunged nearly 513 points Thursday, its biggest point decline since Oct. 22, 2008. Only three of the 500 stocks in the Standard & Poor's 500 index had gains. Oil fell by 6 percent. The yield on the two-year Treasury note hit a record low as investors sought out relatively stable investments.
All three major stock indexes are down 10 percent or more from their previous highs, a drop-off that is considered to be a market correction. A drop of 20 percent or more signifies the start of a bear market, an extended period of stock declines.
Investors are increasingly concerned about the possibility of another recession in the U.S. and a debt crisis in Europe.