While Fools should generally take the opinion of Wall Street with a grain of salt, it's not a bad idea to take a closer look at particularly stock-shaking upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of Pfizer (NYSE:PFE) gained slightly today after Goldman Sachs resumed coverage on the pharmaceutical giant with a buy rating.

So what: Along with the bullish call, analyst Jami Rubin planted a price target of $35 on the stock, representing about 19% worth of upside to Friday's close. So while momentum traders might be turned off by Pfizer's year-to-date price weakness, Rubin's call could reflect a sense on Wall Street that its assets are just too valuable to pass up at the current valuation. 

Now what: According to Goldman, Pfizer's risk/reward trade-off is rather attractive at this point. "Some investors have questioned PFE's motives, yet we think CEO Ian Read has been clear about his strategy: he will do what it takes to unlock value, be it a break-up, M&A or whatever drives the most value," said Rubin. "Our long held view has been that PFE's size is its enemy and that getting smaller could unlock substantial value." More importantly, with Pfizer shares still off about 10% over the past three months and currently boasting a 3.5% dividend yield, the downside seems limited enough to bet on it. 

Brian Pacampara has no position in any stocks mentioned, and neither does The Motley Fool. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.