Analysts are wondering why.

Since the Spanish news outlet Intereconomía reported that Amgen is bidding as much as $200 per share for Alexion Phamaceuticals, analysts have been wondering what the company’s M&A strategy might be.

Alexion, founded in 1992, focuses on the development of treatments for rare diseases. It has worked in the field of complement-mediated diseases and developed several drugs for patients with a number of different diseases in the therapeutic areas of hematology and nephrology, neurology and metabolics.

This focus seems at odds with Amgen’s areas of expertise –– oncology, inflammation and cardiovascular disorders. In addition, according to one analyst, Amgen is currently looking to move away from legacy products and fighting off biosimilars; bringing Alexion’s portfolio into the fold would take the company in the opposite direction. Amgen is developing a biosimilar for one of Alexion’s products that is already in phase III clinical trials.

Another analyst notes that, while Amgen isn’t the most logical buyer for Alexion, Alexion stock is undervalued, which makes it an ideal takeover target for firms that can make larger deals. All of the rumors should at least benefit Alexion, driving up to stock price and finally providing patient shareholders with positive returns.