U.S. shares increase amid mergers in pharmaceutical sector

Wall Street inched higher on Monday trading session rebounding from drops recorded last week as acquisition and merger activity increased among pharmaceutical companies. The Standard & Poor's 500 Index added 0.44% to 1,871.52, the Dow Jones industrial average gained 0.57% to 16,455.29 and the Nasdaq Composite index rose 0.51% to 4,096.34.