U.S. stocks fell sharply on Monday, with the S&P 500 extending losses into a fourth session, as energy companies took it on the chin as the price of oil fell to its lowest since April 2009.
"It looks like the market is largely moving down in conjunction with oil prices, and there's still some fear out there on top it about about Greece possibly exiting the euro zone, and concern about Europe continuing to struggle," said Matthew Kaufler, portfolio manager at Federated Investors.
The CBOE Volatility Index, a measure of investor uncertainty, rose 12 percent to 19.92.
In Greece, Prime Minister Antonis Samaras said the current election campaign could result in a departure from the European Union should the Syriza party win, with the comments helping push the euro to a near nine-year low.
Equities did not get any relief as U.S. automakers reported strong domestic sales in December, with General Motors surpassing estimates and posting a 19 percent gain for the month.