Worst stock market plunge since 2008
The European Union has already given financial assistance to Greece and Ireland, two countries that have struggled to pay their debts. A financial rescue package for Italy or Spain might be more than the group of countries can handle.
Traders also unloaded stocks before Friday's release of the government's unemployment report for July, which is expected to show weak job growth and perhaps a rise in the unemployment rate, which is 9.2 percent.
Together, they produced "a perfect storm of selling," said Ryan Larson, head of U.S. equity trading for RBC Global Asset Management.
Until a week ago, Wall Street had mostly convinced itself that the U.S. economy would improve in the second half of the year. Gas prices were falling, and Japanese factories were resuming production after disruptions from the March earthquake.
Then one report after another began to show that the economy was much weaker than first thought.
Manufacturing is barely growing. The service sector, which covers about 90 percent of the American work force, is growing at the slowest rate in a year and a half. People spent less in June than in May, the first decline since September 2009.
And the overall economy is expanding at the slowest pace since the end of the Great Recession. It grew at an annual rate of just 0.8 percent for the first six months of this year, raising the risk of another recession.
In an indication of how frightened investors are, Bank of New York Mellon said it would start charging large investors to hold their cash because they are depositing so much. The bank's clients include pension funds and large investment houses that are selling stock and need to deposit the proceeds.
Mark Luschini, chief investment strategist for Janney Montgomery Scott, an investment firm in Philadelphia, said his clients saw the move from stocks into cash as "a parking lot to sort things out."
"With the scars of 2008 still fresh," he said, "some clients don't want to miss the chance to pre-empt further damage should it come."
Wells Fargo Advisers, a financial management company in St. Louis, said clients were more nervous.
"I wouldn't say they're totally panicking. But obviously nerves are rattled," said Scott Marcouiller, chief technical market strategist there. "And I think that is simply because of the speed of the decline."
Other market indicators reinforced the risk-averse mood. Gold, which is seen as a safe investment when the stock market is turbulent, set a record price, $1,684.90 an ounce, before falling to finish the day at $1,659. Adjusted for inflation, gold is still far below the record reached in 1980.
The yield on the 10-year Treasury note fell to 2.42 percent, its lowest of the year, and the yield on the 2-year Treasury note hit its lowest ever, 0.265 percent. Bond yields fall when demand for bonds increases.
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