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 analyst upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of Nordson (NDSN -1.30%) gained about 3% today after Global Hunter Securities upgraded the dispensing equipment manufacturer from neutral to buy.

So what: Along with the upgrade, analyst Walt Liptak boosted his price target to $85 (from $80), representing about 10% worth of upside to Friday's close. So while momentum traders might be turned off by Nordson's price weakness in recent weeks, Liptak's call could reflect a sense on Wall Street that its growth prospects are becoming too cheap to pass up.

Now what: Global Hunter boosted its 2014 and 2015 EPS estimates for Nordson from $3.73 to $3.78 and from $4.21 to $4.35, respectively. "Following a review of NDSN's operations, we believe that Q2:14 sales trends are continuing into Q3:14 (July)," said Liptak. "NDSN shares have recently pulled back by ~6%, which sets up what we believe is a buying opportunity. We are moving our Q3:14 sales and EPS to the high end of consensus and believe that the Advanced Tech segment could provide profit upside." When Nordson's still hefty debt load is coupled with its 20-plus P/E, however, it makes sense to wait for a wider margin of safety before betting too heavily on those prospects.