The S&P 500 and Nasdaq opened lower on Wednesday as chip stocks led losses after downbeat results and markets exercised caution ahead of more economic data and the Federal Reserve's interest rate decision later in the day. The Dow Jones Industrial Average rose 29.6 points, or 0.08%, at the open to 37,845.56. The S&P 500 fell 6.7 points, or 0.13%, at the open to 5,029.03.