U.S. equity markets opened lower on Wednesday with the main indexes giving up some of the sharp gains from the previous session after fresh tweets from President Trump suggested he was considering air strikes in Syria. The Dow Jones Industrial Average DJIA, -0.41% fell 179 points, or 0.7%, to 24,235. The S&P 500 index SPX, -0.09% declined 13 points, or 0.5% to 2,643. Meanwhile the Nasdaq Composite COMP, +0.17% was down 31 points, or 0.4% to 7,062 at the open. Among the worst performers on the S&P 500, Fastenal Company FAST, -7.07% shares sold off after quarterly earnings came in slightly below expectations.