Global biotech major Genzyme ( GENZ) attracted $1.1 billion worth of hedge fund purchases in the fourth quarter. John Paulson was a big buyer, snapping up an additional 4.93 million shares to take his total holding to over 6 million. SAC Capital, Eton Park and Farallon Capital were other prominent buyers. After nine months of negotiation, Sanofi- Aventis ( SNY) agreed to buy Genzyme ( GENZ) for $20.1 billion in cash, with additional payments possible depending upon the performance of the latter's drugs. Shareholders will initially receive $74 per share and a potential $14 per share if drugs such as its multiple-sclerosis drug Lemtrada, Cerezyme and Fabrazyme, used to treat rare diseases, meet performance targets. Clearly Paulson's bet on the deal going through paid off. It will be interesting to see the changes in positions in Genzyme in his next quarterly filing now that the terms of the deal are out, as it would likely reflect the hedge fund titan's expectations on the performance of Genzyme's drug pipeline. Most sell-side analysts preferred to sit on the fence on that one, with 17 rating the stock a hold. Only three analysts rate the stock a buy.