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 Hornbeck Offshore Services (NYSE:HOS) gained about 3% this morning after Wunderlich Securities upgraded the offshore drilling services specialist from hold to buy.

So what: Along with the upgrade, analyst Todd Scholl boosted his price target to $55 (from $47), representing about 35% worth of upside to Friday's close. So while momentum traders might be turned off by Hornbeck's sharp pullback over the past six months, Scholl's call could reflect a sense on Wall Street that the risks surrounding its growth prospects are becoming overblown.

Now what: According to Wunderlich, Hornbeck's risk/reward trade-off is rather attractive at this point. "We have tweaked our 2014 EPS estimate to $3.09 from $2.97 and our 2015 EPS estimate to $4.57 from $4.41," said Scholl. "After a period of weakness in the US Gulf of Mexico offshore support vessel market we believe the region is poised to improve in 2H14 as new rig deliveries drive demand that will absorb excess capacity. Our estimates remain cautious but we believe that in 2015 the company should begin generating $9+ in free cash flow per share." When you couple that upbeat outlook with Hornbeck's cheapish EV/EBITDA of 8, it's tough to disagree with Wunderlich's upgrade.