Pfizer (PFE), a stock that doesn't get much respect, is suddenly becoming a favorite with some savvy hedge funds, Reuters reports. And it's all because of Wyeth.

Without Wyeth -- the rival it purchased last year -- Pfizer would be in trouble as sales of its Lipitor cholesterol pill fall off a cliff. Generic versions of the drug are expected to go on sale next year, seriously cutting into Pfizer's revenue.

But with Wyeth under its wing, Pfizer's starting to look good. In the fourth quarter, 11 of the 30 largest equity-oriented hedge funds bought Pfizer stock, according to Thomson Reuters.

By the end of the year, nearly half of the 30 hedge funds owned Pfizer, making it "one of the most popular companies with the smart money set," Reuters reports.

But this is not a stock for the short-term investor. The next couple of years aren't going to bring any dramatic numbers because of patent expirations, one asset manager told Reuters. He's looking for earnings growth in 2013 or 2014.

For evidence of why Wyeth was such a key purchase for Pfizer, consider that before Wyeth, the company only had one vaccine and 16 biotech drugs being tested. Now, Reuters reports, that's up to six vaccines and 27 drugs.

Still, Pfizer has a fair share of skeptics, as its share performance will attest. Shares are only in the mid-$17 range, which is around 8 times expected 2010 earnings.

One portfolio manager told Reuters that drug companies are mostly undervalued. But he's a bigger fan of Amgen (AMGN) and Merck (MRK), which analysts have been bullish on since it bought Schering-Plough.