The Dow Jones industrial average closed below 10,000 Monday for the first time in three months on nagging concerns about debt loads in Europe.
The Dow had its 10th triple-digit move in 16 trading days, falling 103.84, or 1 percent, to 9,908.39. Shares of big banks pulled the market lower, extending a slump that has led to four straight weekly losses.
Mounting deficits in weaker European economies including Greece, Portugal and Spain have raised questions about the health of the global financial system, compounded with concerns about growth in China and proposed U.S. bank regulations.
Greece's finance minister said Monday that the government is preparing to boost some taxes to shore up its finances. But civil servants opposed to cutbacks have pledged to strike Wednesday.
Brett Hryb, of MFC Global Investment Management in Toronto, said the latest concern is that the financial troubles in a country like Greece, whose economy is small, could spill into other countries.