U.S. stocks fell on Monday as investors worried about Greek debt negotiations and disappointing Chinese economic data on top of uncertainty about U.S. interest rates.
After the market's strong week last week, nine out of ten S&P sectors finished down Monday, with healthcare and utilities the worst performers. Only energy finished up slightly, boosted by rising oil prices.
"I think it's just general nervousness about Greece," said Rick Fier, director of trading at Conifer Securities in New York. "When earnings are over, then it becomes a geopolitical type scenario."
Greece's Prime Minister Alexis Tsipras ruled out any extension of its international bailout on Sunday and announced moves to reverse some of the reforms imposed by its lenders. National Bank of Greece's U.S.-listed shares (NBG.N) fell 7.4 percent to $1.12.
China's exports fell 3.3 percent from a year ago while imports tumbled 19.9 percent, far worse than expectations.
The utilities sector .SPLRCU was down 0.9 percent, extending losses from Friday as investors worried about rising interest rates.
"Utilities are trading at very expensive valuations historically, with little earnings and revenue growth," said Michael O'Rourke, chief market strategist at JonesTrading in Greenwich, Connecticut.
"They are truly a reach for yield play, predicated on the low interest rate environment. There's a lot of air to come out of utilities."
High valuations also sent investors away from health stocks .SPXHC, sending that sector down 1.1 percent.
The Dow Jones industrial average .DJI fell 95.08 points, or 0.53 percent, to 17,729.21, the S&P 500 .SPX lost 8.73 points, or 0.42 percent, to 2,046.74 and the Nasdaq Composite .IXIC dropped 18.39 points, or 0.39 percent, to 4,726.01.
Monday's retreat came after all three major indexes showed strong gains last week, with the Dow industrials rising 3.8 percent for its biggest weekly gain since January 2013.
Achillion Pharmaceuticals (ACHN.O) rose 7.8 percent on news its experimental hepatitis C drug, used with Gilead Sciences Inc's (GILD.O) Sovaldi, eradicated signs of the virus after six weeks.
Oil prices climbed for a third straight session, lifting the S&P energy sector .SPNY for most of the day after OPEC forecast greater demand.
Despite some high-profile misses from multinationals, Thomson Reuters data through Monday morning showed 72.6 percent of the 328 S&P 500 companies have beat earnings expectations, above the 69-percent beat rate for the past four quarters.
About 6.2 billion shares changed hands on U.S. exchanges, below the 7.8 billion average for the last five sessions, according to BATS Global Markets.
Declining issues outnumbered advancers on the NYSE by 1,826 to 1,256, for a 1.45-to-1 ratio; on the Nasdaq, 1,730 issues fell and 1,014 advanced, a 1.71-to-1 ratio.
The S&P 500 posted 11 new 52-week highs and 3 new lows; the Nasdaq Composite recorded 48 new highs and 25 new lows.