Stocks are off to a mixed start on
Biogen soared 40% after the drug company said it would seek federal approval for a medicine to treat early Alzheimer's disease.
Financial companies were lagging the rest of the market. Travelers sank 7% after the insurance company reported earnings that fell far short of analysts' forecast.
Hasbro plunged 15% after the toymaker reported weak quarterly results.
The S&P 500 edged up 2 points, or 0.1%, to 3,009.
The Dow Jones Industrial Average fell 16 points, or 0.1%, to 26,812. The Nasdaq gained 20 points, or 0.3%, to 8,183.
Bond prices rose. The yield on the 10-year