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 Apple (NASDAQ:AAPL) gained slightly in pre-market trading Thursday after Deutsche Bank initiated coverage on the consumer electronics gorilla with a buy rating.

So what: Along with the bullish call, analyst Sherri Scribner planted a price target of $650 on the stock, representing about 23% worth of upside to yesterday's close. So while momentum traders might be turned off by Apple's sluggish price action in recent months, Scribner's call could reflect a growing sense on Wall Street that the company's growth prospects are becoming too cheap to pass up.

Now what: According to Deutsche, Apple's risk/reward trade-off is rather attractive at this point. "While growth is expected to decelerate in both [iPhone and iPad] markets, industry growth remains robust, with smartphones expected to grow units in the high teens for the foreseeable future and tablets expected to grow in the mid-20%s," noted Scribner. "We expect iPhones and iPads to be the key growth driver for Apple over the next year, with further upside in iPhones coming from a larger screen sized phone and further penetration in emerging markets." When you couple that upbeat view with Apple's cheapish forward P/E of 11, it's tough to disagree with Deutsche's bullishness.

Brian Pacampara has no position in any stocks mentioned. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple. 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.