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 Finisar (NASDAQ:FNSR) climbed as high as 5% today after Jefferies upgraded the optical products technologist from underperform to hold.

So what: Along with the upgrade, analyst James Kisner drastically boosted his price target on Finisar stock to $22.50 (from $11.50), representing just 4% worth of downside to yesterday's close. While Kisner isn't exactly bullish on the hot stock's appreciation potential, he thinks that strong data center spending should at least be able to minimize the downside.

Now what: According to Jefferies, Finisar's risk and reward pretty much cancel each other out at these levels. "We're upgrading FNSR from Underperform to Hold driven by 2 key factors: 1) our checks suggest that Data Center spending on 10G/40G optics is likely to remain quite strong in the near- to medium-term; 2) our checks also suggest a significant commercial impact ramp of silicon photonics is likely at least 6 months away," noted Jefferies. "We continue to believe silicon photonics presents significant pricing and market share risk for FNSR." Of course, with Finisar up about 120% from its 52-week lows, trading at a 80-plus P/E, and sporting a beta of 1.9, I'd even go one step further and say that Finisar shares seem particularly risky. 

Fool contributor Brian Pacampara has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. 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.