SP ends flat as biotech selloff offsets Yellen comments
The Dow Jones industrial average rose 113.35 points, or 0.7 percent, to 16,314.67, the SP 500 lost 0.9 points, or 0.05 percent, to 1,931.34 and the Nasdaq Composite dropped 47.98 points, or 1.01 percent, to 4,686.50.