The dollar hit a more than one-week high against a basket of currencies and the euro eased on Monday, while US stocks were little changed after starting 2018 with strong gains registered last week.
Investors took profits in the euro after the common currency's recent rally. The dollar index, which measures the greenback against six rival currencies, was up by 0.4 per cent at 92.321.
The euro slipped 0.48 to $1.197. The euro hit a nearly four-month high of $1.2089 last week.
"The euro got a little bit over its skies when it traded over $1.20," said Brad Bechtel, managing director FX at Jefferies in New York.
"It's a little been of profit taking and some healthy correction going on the euro's side, which is driving some of the dollar trades," Bechtel said.
The S&P 500 was trading slightly lower, while an global index of equities also was little changed. Healthcare and financial stocks were a drag on the S&P 500.
A surprise dip in German industrial orders
The Dow Jones Industrial Average fell 31.76 points, or 0.13 per cent, to 25,264.11, the S&P 500 lost 0.36 points, or 0.01 per cent, to 2,742.79 and the Nasdaq Composite added 13.87 points, or 0.19 per cent, to 7,150.42.
The pan-European FTSEurofirst 300 index rose 0.26 per cent and MSCI's gauge of stocks across the globe shed 0.01 percent.
A surprise dip in German industrial orders, which fell in November for the first time since July, appeared unlikely to dent growing confidence in the euro zone's biggest economy after a strong run of positive economic news.
With the New Year's Day holiday falling on a Monday this year, it was the strongest first four trading days of a year in more than a decade for all three major US stock indices, according to Reuters data. For the Dow, it was the strongest start since 2003 and for the Nasdaq and S&P 500 it was the strongest since 2006.
Attention in the United States now turns to the quarterly earnings season, with results from JPMorgan Chase due Friday.
In the US Treasury market, bond yields were modestly lower after data on Friday showing an unexpectedly slower growth in US hiring for the month of December.
Benchmark 10-year notes last fell 3/32 in price to yield 2.4873 per cent, from 2.476 per cent late on Friday.
Oil prices were slightly higher. A slight decline in the number of US rigs drilling for new production kept prices in check.
US crude rose 0.15 per cent to $61.53 per barrel and Brent was last at $67.68, up 0.09 percent on the day.