U.S. stocks were little changed on Monday after a modest rise that lifted the Nasdaq composite index above 4,000 for the first time since September 2000.
World powers and Iran reached a deal on Sunday in which Iran agreed to partially curb its nuclear program. Oil prices fell, pressuring energy stocks.
Trading is expected to be light this week, with U.S. markets closed Thursday for Thanksgiving and finishing early on Friday. The light action could increase market volatility. The CBOE Volatility index .VIX is down more than 30 percent this year, and is at historically low levels, which could make it vulnerable to a spike.
The market has room to go higher, analysts said, even though the S&P 500 is up 26.5 percent for the year and the Dow rose seven weeks in a row.
"Not surprisingly, many investors are asking whether this sets us up for some type of pullback. In our view, the answer is a resounding 'No.' While these results are excellent, especially in the context of weak economic and earnings growth, they are hardly out of the ordinary," said Jonathan Golub, chief U.S. market strategist at RBC Capital Markets in New York.
"Since 1965, the S&P 500's forward price-earnings ratio has averaged 14.1 times. The market multiple currently sits at 15 times, hardly out of the norm."
The Dow Jones industrial average .DJI was up 33.59 points, or 0.21 percent, at 16,098.36. The Standard & Poor's 500 Index .SPX was up 1.19 points, or 0.07 percent, at 1,805.95. The Nasdaq Composite Index .IXIC was up 3.01 points, or 0.08 percent, at 3,994.66 after hitting 4007.
U.S. crude futures fell 1.3 percent after the breakthrough nuclear deal, which will ease some of the economic sanctions for Iran. Brent crude fell 1.6 percent.
Energy shares .SPNY were by far the weakest on the day, dropping 0.7 percent. Among the most active stocks, WPX Energy Inc (WPX.N) fell 2 percent to $18.56 and Newfield Exploration (NFX.N) lost 3.4 percent to $29.01.
Despite the pressure on the energy sector, the deal was viewed as having positive benefits for the market at large.
"Less tension in the Middle East is always a positive, and any drop in gas prices will essentially act as a tax break for consumers going into the holiday shopping season," said Jeff Duncan, chief executive of Duncan Financial Management in St. Louis. "This is a real benefit for the economy."
Facebook (FB.O) and Yelp YELP.O continued their recent decline. Facebook shares fell 3.8 percent to $44.49 and Yelp fell 7.9 percent to $57.53. Twitter shares TWTR.O also fell 4.7 percent to $38.94.
If history is a guide, Wall Street faces a promising outlook in December, which has been the best month for both the Dow and the S&P since 1950. If this year's trend continues, it will be the best year for the broad index since 1998.
In company news, Wal-Mart Stores Inc (WMT.N) edged 0.8 percent higher to $80.43 after the retailer named Doug McMillon its new chief executive officer, effective February 1, succeeding Mike Duke. McMillon is currently the president and chief executive of the Dow component's international segment.
DaVita HealthCare Partners Inc (DVA.N) rose 6.8 percent to $60.39 after giving a 2014 enterprise operating income outlook. The stock was the biggest gainer on the S&P 500, followed by Alcoa Inc (AA.N), which jumped 3.4 percent to $9.55 after Goldman Sachs upgraded the stock.