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 Fortinet Inc. (NASDAQ:FTNT) climbed 2% today after JMP Securities upgraded the network security technologist from Market Perform to Outperform.

So what: Along with the upgrade, analyst Erik Suppinger planted a price target of $26 on the stock, representing about 21% worth of upside to yesterday's close. While contrarians might be turned off by Fortinet's sharp rebound since its big December drop, Suppinger thinks there's plenty of room to bounce given the seemingly strong enterprise security tailwinds working in its favor.

Now what: According to JMP, Fortinet's risk/reward trade-off is rather attractive at this point. "We believe the managed security service provider market is healthy and that the company is well positioned to accelerate share gains against competitors, such as [Juniper Networks]," noted Suppinger. "We also believe that the rash of security breaches in recent months is accelerating demand for enterprise security, particularly in the distributed enterprise, where Fortinet is particularly well positioned." Of course, with Fortinet's highly volatile shares up 30% since December 1st and trading at a P/E of 70, I'd wait for a much wider margin of safety before betting on it.