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 LinkedIn Corp. (LNKD.DL) climbed about 3% in premarket trading after RBC Capital upgraded the online professional network from sector perform to outperform.

So what: Along with the upgrade, analyst Mark Mahaney boosted his price target to $250 (from $225), representing about 20% worth of upside to yesterday's close. While momentum traders might be turned off by LinkedIn's share-price weakness in recent months, Mahaney thinks that Mr. Market might be overestimating the risks surrounding its growth going forward. 

Now what: According to RBC, LinkedIn's risk/reward trade-off is pretty attractive at this point. As Mahaney noted:

Drag Issues have included: 1) overly aggressive Street estimates, 2) a heavier than expected investment outlook for '14, 3) a greater-than-expected slowdown in Talent Solutions revenue growth, and 4) uncertainty over Marketing Solutions format changes. The first issue has been addressed -- Street '14 EBITDA estimates have been reduced 11% since the beginning of this year. And we believe LNKD's '14 investments -- salesforce buildouts, product and market expansions, and acquisitions -- are coming from a position of strength against large TAMs. Our very recent proprietary work helps address Drag Issues 3 & 4.

When you couple that improving outlook with LinkedIn's still-sluggish stock price -- off about 20% from its 52-week highs -- it's tough to disagree with LinkedIn's upgrade.