(CNBC) — U.S. stocks closed mostly lower on Monday as investors reassessed the prospects of key White House proposals, including tax reform, coming to fruition.

“When you look at some of the areas that have helped the market, they are waning a bit here,” said Daniel Deming, managing director at KKM Financial. “I think you’re also seeing some valuation concerns as well.

The Nasdaq composite closed 0.2 percent higher after briefly falling 1 percent.

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