We run a series here at the Fool pointing out that a famous investor bought or sold a stock and then wondering whether you should follow suit, but the title of this one is rhetorical. I hope.

The fact that the head of the U.S. Supreme Court, Chief Justice John Roberts, sold his shares in Pfizer (NYSE: PFE) is getting a lot of press, but it isn't really relevant to investors -- unless you need to remove a conflict of interest to hear a court case, of course.

I do wonder if people blindly follow the gurus though. How many people try to mimic Warren Buffett's moves at Berkshire Hathaway (NYSE: BRK-A) (NYSE: BRK-B) without any regard for how Berkshire Hathaway's needs are completely different than their own? Buffett has even admitted the stupidity of the idea, pointing out that investors can make money buying small cap stocks that he can't touch because he has too much money to invest.

The answer to whether you should buy or sell Pfizer depends on the needs for your portfolio and your view of Pfizer's chances to succeed.

The best thing going for Pfizer right now is its solid 4.1% dividend yield. But that level or better is available from other pharmaceutical companies: Eli Lilly (NYSE: LLY) and Bristol-Myers Squibb (NYSE: BMY) sport higher dividends, while Merck (NYSE: MRK) is on par with Pfizer. You really need a reason for owning Pfizer over other drugmakers.

The integration of Wyeth is going well, and the added revenue will make the loss of Lipitor next year sting a little less. But the company needs to find a way to replace those lost sales and then some to grow. Replacing $12 billion is a difficult challenge.

So should you sell Pfizer? I can see how Pfizer could fit into some conservative portfolios, but many people would be better off with a midsized drugmaker that's growing -- think Gilead Sciences (Nasdaq: GILD) -- or larger pharmaceutical company that has a well-stocked pipeline -- consider Bristol-Myers. Whatever you do, don't sell Pfizer solely because Roberts did.

If you need more alternatives to Pfizer, consider the biotechs that this billionaire likes.