Stock market numbers are displayed on a screen at the New York Stock Exchange in New York City. The S&P 500 closed 0.37 per cent lower at 4,409.59. Getty Images via AFP
Stock market numbers are displayed on a screen at the New York Stock Exchange in New York City. The S&P 500 closed 0.37 per cent lower at 4,409.59. Getty Images via AFP

US stocks rally is about to run out of steam, Citigroup says