Biogen has proposed to acquire Sage Therapeutics for $442 million, offering a 30% premium at $7.22 per share. This unsolicited offer comes as Sage's stock has surged significantly, climbing 40% recently due to high short interest, which has led to substantial losses for short sellers. Analysts note that Biogen, already a partner and equity owner of Sage, has made this move amid ongoing evaluations of Sage's drugs and a cash reserve of $560 million. Despite the offer, Sage's management expressed surprise and stated they had no desire to sell the company. The acquisition proposal was discussed during a meeting between analysts and Biogen management, where it was indicated that the urgency for such deals has decreased due to progress in other projects, including lupus treatments.