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 Intel Corporation (INTC -9.20%) climbed 3% this morning after Citigroup upgraded the chip gorilla from neutral to buy.

So what: Along with the upgrade, analyst Glen Yeung reiterated his price target of $28, representing about 15% worth of upside to yesterday's close. While momentum traders might be turned off by the stock's sluggish 2013, Yeung believes that stabilizing consumer PC and enterprise demand should serve as positive catalysts in 2014.

Now what: For the first time since 2008, Citigroup's model for corporate PC demand is greater than that of consumer demand. And while consumer demand remains particularly sluggish, Yeung believes that Intel's PC shipment guidance for 2014 is sufficiently conservative. When you combine those seemingly reasonable expectations with Intel's still-dominant scale, it's tough to disagree with Citi's upgrade.