Shares of Portola Pharmaceuticals (NASDAQ: PTLA) -- a biopharmaceutical company that focuses on the development of treatments for life-threatening blood disorders -- are up by a whopping 129% as of 12:11 p.m. EDT on Tuesday. The company's shares more than doubled following the news that Portola reached an agreement to be acquired by Alexion Pharmaceuticals (NASDAQ: ALXN).
Alexion will launch a tender offer to acquire all the outstanding shares of Portola for $18 per share in cash. Note that Portola closed at about $7.76 per share yesterday, which means the proposed price of this acquisition represents a significant premium over Portola's stock price, at least as of the closing of the market on Monday. This factor explains why investors loaded up on Portola's shares and drove its stock price significantly higher today. After an active morning trading session, Portola's shares are now worth approximately $17.80 apiece.
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