In early trading on Tuesday, shares of Alexion Pharmaceuticals topped the list of the day's best performing components of the Nasdaq 100 index, trading up 3.1%. Year to date, Alexion Pharmaceuticals registers a 12.6% gain.
And the worst performing Nasdaq 100 component thus far on the day is MercadoLibre, trading down 4.7%. MercadoLibre Inc is showing a gain of 85.8% looking at the year to date performance.
Two other components making moves today are Idexx Laboratories, trading down 3.7%, and Hasbro, trading up 2.6% on the day.