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 FARO Technologies (NASDAQ:FARO) rallied 6% today after Needham upgraded the 3-D measurement technologist from hold to buy.

So what: Along with the upgrade, analyst James Ricchiuti planted a price target of $50 on the stock, representing about 17% worth of upside to yesterday's close. So while momentum traders might be turned off by FARO's price pullback in recent months, Ricchiuti's call could reflect a sense on Wall Street that the company's growth prospects are becoming too cheap to pass up.

Now what: According to Needham, FARO's risk/reward trade-off is rather attractive at this point. "At a conference this week, mgmt again suggested that mid-teens rev growth is reasonable for 2014," said Ricchiuti. "FARO continues to see stable pricing in the core industrial metrology business, consistent with solid end-market demand. Mgmt also downplayed the impact of the shift in its go-to-market strategy for the new Focus 3D X330 scanner as it builds out a new reseller channel while continuing its own direct sales of the product." When you couple that upbeat outlook with the stock's recent weakness, it's tough to disagree with Needham's bullishness.