S&P 500 Movers: COO, ALXN
December 08, 2017 at 10:16 AM EST
In early trading on Friday, shares of Alexion Pharmaceuticals (ALXN) topped the list of the day's best performing components of the S&P 500 index, trading up 6.5%. Year to date, Alexion Pharmaceuticals has lost about 7.0% of its value.