Technology shares led U.S. equities lower as investors weighed the latest corporate earnings and the chances of a trade breakthrough between the world's biggest economies.
The Nasdaq 100 tumbled more than 1 percent, with Twitter, Facebook and chipmakers leading declines ahead of earnings by Apple and AMD after the bell. Industrial companies fared better as 3M Co. struck an optimistic tone after reporting a profit that beat estimates.
The S&P 500 Index fell 0.4 percent and Dow down 13 points, or 0.1%.
After a robust start to the year for equities, investors are looking for direction from a corporate earnings season that's been indecisive so far.