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

What: Shares of Sotheby's (NYSE:BID) climbed 2% in early trading after Citigroup upgraded the auction house to "buy" from "neutral."

So what: Along with the upgrade, analyst Oliver Chen boosted his price target on the stock to $55 per share (from $45), representing about 16% worth of upside to yesterday's close. Chen cited several potential catalysts for the call, including the potential sale of its headquarters, a return of capital to shareholders, and even a possible leveraged buyout.

Now what: At the very minimum, I expect management to make some strategic tweaks and start focusing on less expensive goods. "Sotheby's current focus on high-end property may leave the company vulnerable to competition on commission margins and sellers of high-end property could be more likely to leave the market during pullbacks which exposes Sotheby's to greater volatility," Chen said. So while the stock is hitting a new 52-week high today, Citigroup's price target doesn't seem all that unreasonable given the many number of potential catalysts working in Sotheby's favor. 

Fool contributor Brian Pacampara has no position in any stocks mentioned. The Motley Fool recommends Sotheby's. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.