After initially calming markets, the excitement around the Federal Reserve's comments on tariffs and rates seemed to fizzle out as stock futures fell in premarket trading Thursday U.S. stock markets n

U.S. stock index futures reversed early gains on Thursday, as worries about the fallout of U.S. tariff policies crept back into markets a day after the Federal Reserve stuck to its monetary easing plans for the year but warned of an uncertain economic backdrop.

The Fed opted to maintain current interest rates on Wednesday, a move widely anticipated by the market, but reaffirmed its forecast for two 25 basis point reductions by the year-end. However, the central bank revised its economic outlook,