US stocks closing: U.S. stocks edged lower on Monday as caution over the potential for volatility driven by worries about the U.S. "fiscal cliff" dampened enthusiasm at the start of a seasonally strong period for equities.
Investors are betting Congress will reach a deal to avert most of the austerity measures due to come into force at the start of next year. That has led to the best year for stocks since the post-financial crisis rebound. But those gains may be quickly reversed if a deal is not reached soon.
The S&P 500 index posted its biggest drop in more than a month on Friday as a Republican plan to avoid the cliff - $600 billion in tax hikes and spending cuts that could tip the U.S.
economy into recession - failed to gain traction on Thursday night.
Sharp moves like that highlight how headlines from Washington can whipsaw markets, especially during the thinly traded period over the Christmas holiday.
Still, with the S&P 500 up 0.7 percent in December and on course for its strongest month since September, some analysts are predicting that stocks will find their footing during a market seasonality known as the "Santa Claus rally."
"Right now we've seen some very constructive action in the market so I think that bodes well for this being a positive seasonal 'Santa' period over the coming seven days," said Ari Wald, a technical analyst at The PrinceRidge Group.
He noted an all-time high in the NYSE advance-decline line, which compares advancing and declining stocks, as indication of strong participation in the rally off November lows.
"Pull-backs are buying opportunities," said Wald. "There has been really great participation on this move, a lot of small- and mid-cap stocks behaving well, pushing out to the upside; we're seeing some good leadership from offensive sectors of the market as well."
A high ratio of advancing stocks to declining issues shows there is broad participation across the equity market.
The Santa seasonality covers the last five trading days of the year and the first two of the new year. Since 1928, the S&P 500 has averaged a gain of 1.8 percent during this period and risen 79 percent of the time, according to data from PrinceRidge.
The Dow Jones industrial average dropped 51.76 points, or 0.39 percent, to 13,139.08. The Standard & Poor's 500 Index fell 3.49 points, or 0.24 percent, to 1,426.66. The Nasdaq Composite Index lost 8.41 points, or 0.28 percent, to