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 Expedia (NASDAQ:EXPE) gained 2.5% in pre-market trading Tuesday after Susquehanna upgraded the online travel company from neutral to positive.

So what: Along with the upgrade, analyst Brian Nowak boosted his price target to $90 (from $79), representing about 21% worth of upside to yesterday's close. So while contrarian traders might be turned off by Expedia's year-to-date price sluggishness, Nowak's call could reflect a sense on Wall Street that the concerns surrounding the company's growth trajectory are becoming overblown.

Now what: Susquehanna maintained its Street-high 2014 earnings-per-share estimate for Expedia and raised its 2015 outlook by 5%. "Our updated breakdown of EXPE's 3 main businesses (Travelocity, Trivago, and "core") shows how Street EPS numbers are 3% and 4% too low in '14 and '15 even using conservative assumptions," said Nowak. "In a sector where we expect upward revisions to drive out-performance, we turn to EXPE and raise our PT to $90." When you couple that upbeat outlook with Expedia's reasonable forward P/E in the midteens, it's tough to disagree with Susquehanna's bullishness.