U.S. stocks ended lower but off their lows of the day on Wednesday as the Federal Reserve held interest rates steady as expected and Fed Chair Jerome Powell offered soothing comments on the economy.

Investors around the world are reassessing the prospects for technology companies after a Chinese artificial intelligence start-up rocked markets in the United States on Monday.

Tech stocks nudged lower on Tuesday with chipmaker Nvidia falling 2% in early trade, a day after it suffered the biggest one-day market capitalisation loss in history, though traders did shift back out of safe-haven currencies into the dollar.