The S&P 500 index was down 0.1% as of 12:15 p.m. ET, the Dow Jones Industrial Average was down 0.2%, and the Nasdaq composite was down less than 0.1%. Institutional investors are largely closed out of their positions for the year. The S&P 500 has climbed nearly 18% this year, helped by the deregulatory policies of the Trump administration as well as investor optimism about the future of artificial intelligence.