"Despite some weakness in consumer confidence, people are still spending money," David Lebovitz, global market strategist for J.P. Morgan Funds, said of monthly sales figures from auto manufacturers.
U.S. automobile sales rose 4.6 percent in November to 1.3 million, Autodata reported, with the auto sales rate coming to 17.2 million last month in the strongest pacefor the month since 2003.
The auto sales "indicate the economy's momentum remains on track, and is moving along, basically on all fronts," said Peter Cardillo, chief market economist at Rockwell Global Capital.
Stocks maintained gains after the Commerce Department reported construction spending rose 1.1 percent in October.
BP climbed on unconfirmed talk of a takeover bid for the U.K. energy company from Royal Dutch Shell; RadioShack fell as the electronics retailer rejected claims it had breached covenants on a term loan from Harbinger Group unit Salus Capital Partners.
Apple fell, extending losses that followed its largest single-day decline since September.
Energy costs were on the retreat again, with crude futures for January delivery falling $2.12, or 3.1 percent, to $66.88 a barrel.
"Oil prices are a double-edged sword," said Lebovitz, saying the drop is obviously not good for oil producers who represent 30 percent of capital expenditures among the S&P 500 companies.
"But the other side of the coin is it is good for the consumer, as lower oil prices mean lower gas prices, and in a consumption-based economy that provides a strong tail wind to consumer spending," Lebovitz said.
Lebovitz and other analysts downplayed a report from IBM Digital Analytics that showed Cyber Monday online sales grew from last year, but at a slower pace.
"Black Friday and Cyber Monday are not statistically significant in terms of predicting the overall holiday season," offered Lebovitz of the traditional sales period where retailers offer holiday promotions.