The Dow and the S&P 500 were little changed, while the Nasdaq was firmly higher, propped up by the high-flying technology trio of Apple, Amazon and Microsoft.
The S&P tech sector was up 0.2 percent. Tech stocks have been at the center of a sharp recovery in the S&P since a market rout in February, driving the index close to its record high.
Shares of Apple rose 1 percent, while those of Amazon were up 0.5 percent and Microsoft 0.3 percent.
"The S&P has been climbing gradually amid geopolitical and trade concerns," said Andre Bakhos, managing director at New Vines Capital LLC in Bernardsville, New Jersey.
"Investor mindset has been predicated on a strong economy and a longer-term perspective, and that has been playing out very nicely."
The number of Americans filing for unemployment benefits unexpectedly fell last week, suggesting that a strong economy was helping the labor market counter ongoing trade tensions.
At 9:50 a.m. EDT the Dow Jones Industrial Average was down 14.63 points, or 0.06 percent, at 25,569.12, the S&P 500 was unchanged at 2,857.70 and the Nasdaq Composite was up 11.39 points, or 0.14 percent, at 7,899.72.
Seven of the 11 main S&P sectors were higher. The materials sector led the gains as aluminum prices rose.
Sinclair dropped 4 percent after Tribune Media ended its $3.9 billion deal to be acquired by Sinclair and filed suit. Tribune shares rose 2.2 percent.
Rite Aid fell 10.9 percent after the drug store chain and U.S. grocer Albertsons Cos agreed to terminate their merger agreement.
Chip stocks fell after Morgan Stanley downgraded the U.S. semiconductor industry saying upside to estimates is difficult to come by.
Lam Research, Micron, Applied Materials and ON Semiconductor fell between 1 percent and 4.7 percent.
Advancing issues outnumbered decliners by a 1.68-to-1 ratio on the NYSE and by a 1.58-to-1 ratio on the Nasdaq.
The S&P index recorded 20 new 52-week highs and one new low, while the Nasdaq recorded 44 new highs and 24 new lows.