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

What: Shares of Garmin Ltd. (NASDAQ:GRMN) climbed 3% on Wednesday after Citigroup upgraded the GPS technologist from neutral to buy.

So what: Along with the upgrade, analyst Jeremy David boosted his price target to $65 (from $50), representing about 20% worth of upside to yesterday's close. So while contrarians might be turned off by Garmin's share-price surge over the past year, David's call could reflect a strengthening sense on Wall Street that its growth prospects give it plenty of room to run.

Now what: According to Citigroup, Garmin's risk/reward trade-off remains particularly attractive at this point. "While we have been cautious on the VIRB action camera, and continue to be cautious, we are excited about the prospects for vivofit," said David. "We believe Garmin can become a top 2 player in the activity monitor market over the next 6 months -- vivofit is the only wrist-based activity monitor with a 1+year battery life, and it is reasonably priced, making it well positioned to win customers considering price and battery life are the top two features buyers look for." Of course, with the stock now up about 75% from its 52-week highs and trading at a steep-ish PEG of 3, I'd wait for a much wider margin of safety before betting on it. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.