The Federal Reserve left interest rates unchanged, as expected, but made a slightly hawkish adjustment to its policy statement. Markets could swing during Chairman Jerome Powell's 2:30 p.m. ET news conference based on his assessment of current labor market conditions and whether he plans to continue to serve on the Fed after his chairmanship ends on May 15. The S&P 500 remained slightly lower shortly after the 2 p.m. ET policy statement on Wednesday after eking out a record closing high on Tuesday.