Alexion (ALXN) reported Q4 revenue of $599M above consensus. Q4 non-GAAP EPS of $1.30 also beat consensus. Alexion gave 2015 revenue guidance below consensus blaming a headwind of -5% on USD strength. Alexion also guided 2015 cogs, r&d and sg&a below 2014 as a percent of revenue, implying a margin improvement. Finally, Alexion guided to a much lower tax rate of 13%. The market has taken all of this to be a net positive, and ALXN is up +5.6%. I like ALXN as a buy on weakness.