Why Is Biogen Idec on the Rise?

Biogen Idec (BIIB) has continued to fight off Carl Icahn, opposing his nominees to the company's board and setting up a fight at the annual meeting later this year.

But Tuesday morning (as a correspondent has just pointed out to me) the company's stock seemed to be taking off. It was up about 7%, with the broad market down, and all of this rise seems to have been since 11 AM. Someone's stepping up and buying a good amount of BIIB, for some reason. But who, and why?

Update: ah, here we go - rumors of Sanofi-Aventis (SNY) or some other non-Icahn entity stepping in. We'll see if there's anything to it. . .