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 Sotheby's (NYSE:BID) rallied 4% today after Barrington Research initiated coverage on the auction house operator with an outperform rating.

So what: Along with the bullish call, analyst Kristine Koerber planted a price target of $52 on the stock, representing about 24% worth of upside to yesterday's close. So while momentum traders might be turned off by Sotheby's year-to-date price weakness, Koerber's call could reflect a sense on Wall Street that its growth prospects are becoming too cheap to pass up.

Now what: According to Barrington, Sotheby's risk/reward trade-off is rather attractive at this point. "We believe favorable demographics and recent auction sales are positive signs for the market and Sotheby's," said Koerber. "We believe wealth creation should continue to fuel the art market for at least the next year as it appears to be a more globally diverse art market cycle than in the past." When you couple that upbeat outlook with Sotheby's sluggish stock price -- still off about 20% from its 52-week highs -- and forward P/E of 15, it's tough to disagree with Barrington's bullishness.