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 Credit Suisse Group AG (NYSE:CS) gained about 1% today after Deutsche Bank upgraded the Swiss financial services giant from hold to buy.

So what: Along with the upgrade, analyst Matt Spick raised his price target to CHF 31 (from CHF 30), representing about 15% worth of upside to yesterday's close. So while momentum traders might be turned off by Credit Suisse's pullback in recent weeks, Spick's call could reflect a sense on Wall Street that its growth prospects are becoming too cheap to pass up.

Now what: According to Deutsche, Credit Suisse's long-term risk/reward trade-off is rather attractive at this point. "Our forecasts for profit and CET1 for 2014E are revised down, but our 2015E profit forecasts are intact, and we expect capital to rebuild steadily as Credit Suisse works on reducing FICC RWAs further," said Spick. "Over time, we expect this to work to the advantage of the share price, given that we see Credit Suisse as inching closer to the WM / Equities model of investment banking." When you couple that upbeat outlook with Credit Suisse's reasonable valuation -- P/B of one and a 2.5%-plus dividend yield -- it's easy to understand Deutsche's bullishness.