US stocks headed lower Thursday after rising strongly for two straight sessions driven by Congress's long-awaited deal to avert the economy-crunching fiscal cliff.
Around 30 minutes into trade, the Dow Jones Industrial Index was down 36.05 points (0.27 percent) at 13,376.50.
The broad-based S&P 500 slipped 2.47 (0.17 percent) to 1,459.95, while the Nasdaq Composite lost 2.62 points, or 0.08 percent, at 3,109.64.
On Wednesday the markets opened the New Year with a grand rally, the S&P 500 surging 2.5 percent and the Nasdaq gaining 3.1 percent.
The fallback recognized that the high-stakes battles over the US debt and deficit are not finished, with another round of brinksmanship between warring Democrats and Republicans already beginning.
"The fiscal cliff deal has put some important questions to rest. It has averted most -- but not all -- of the tax increases that otherwise would have kicked in at the beginning of 2013," said Nigel Gault of IHS Global Insight.
However, he added, "the deal leaves major questions unanswered," including just postponing programmed steep spending cuts and not raising the country's statutory debt ceiling. That borrowing barrier "will soon become a binding restraint on government spending," Gault said.
Retailer Family Dollar sank 13.1 percent after missing expectations for earnings in its fiscal first-quarter report. Rival Dollar General also lost ground, falling 5.3 percent.
Other retailers however picked up ground: Ross Stores (+6.7 percent), TJ Maxx owner TJX (+3.5 percent) and Nordstrom (+2.6 percent).
Abbott Laboratories gained 2.5 percent a day after it finished hiving off its pharmaceuticals unit AbbVie, which slipped nearly 1.0 percent.
Bond prices were generally flat. The yield on the 10-year US Treasury was at 1.84 percent, while the 30-year held at 3.05 percent.