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 Mobile Mini, Inc. (NASDAQ:MINI) climbed 4% today after Deutsche Bank initiated coverage on the portable storage solutions company with a buy rating.

So what: Along with the bullish call, analyst Amit Mehrotra planted a price target of $57 on the stock, representing about 23% worth of upside to Friday's close. So while contrarian traders might be turned off by Mobile Mini's strong rebound over the past year, Mehrotra's call could reflect a sense on Wall Street that its turnaround potential still isn't fully baked into the valuation.

Now what: According to Deutsche, Mobile Mini's risk/reward trade-off remains particularly attractive at this point. "We see 30% upside in shares of Mobile Mini as its relatively new, highly capable management team accelerates the company's transformation from a strong, but undermanaged company to best-in-class with deep logistical capabilities and significant pricing power," said Mehrotra. "The restructuring efforts should translate to 13% and 27% CAGR revenue and EPS growth through 2017, driven by a significant increase in the utilization of MINI's lease fleet and a step-function improvement in profitability." Of course, with Mobile Mini shares now up 75% from its 52-week highs and trading at a forward P/E of 30, I'd wait for a wider margin of safety before betting too heavily on that upbeat outlook.