Technology stocks lifted U.S. stock indexes higher at the open on Thursday after a sharp fall in the previous session, with investors closely tracking a meeting of Western leaders as the Ukraine crisis enters its second month. The Dow Jones Industrial Average rose 48.31 points, or 0.14 percent, at the open to 34,406.81. The S&P 500 opened higher by 13.74 points, or 0.31 percent, at 4,469.98, while the Nasdaq Composite gained 78.72 points, or 0.57 percent, to 14,001.32 at the opening bell.