Threat of 'hard Brexit' pulls down Wall Street

Angst about future interest rate hikes also returned to the fore after Richmond Federal Reserve President Jeffrey Lacker said he would have voted in favor of an increase at the latest policy meeting had he been able to do so. Meanwhile, the International Monetary Fund lowered its 2016 growth forecast for the U.S. economy to 1.6 percent from 2.2 percent and painted a gloomy picture of the global economy. The Nasdaq Composite dropped 0.21 percent to 5,289.66.