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 Qualcomm (NASDAQ:QCOM) gained slightly in pre-market trading Wednesday after Northland Capital Markets upgraded the mobile chipset gorilla from market perform to outperform.

So what: Along with the upgrade, analyst Tom Sepenzis planted a price target of $90 on the stock, representing about 10% worth of upside to yesterday's close. So while contrarian traders might be turned off by Qualcomm's price strength over the past year, Sepenzis' call could reflect a sense on Wall Street that sector tailwinds give the stock plenty of room to run.

Now what: According to Northland, Qualcomm represents a particularly timely opportunity. "Qualcomm reports tonight, what should be a pretty solid quarter driven by LTE growth in multiple new markets," said Sepenzis. "While it is experiencing competition in China and other emerging regions, the overall growth in LTE should help the chipmaker top our forecast and consensus. We are currently modeling $6.4 billion in revenue and $1.21 for the June quarter vs. consensus of $6.5 and $1.22 in EPS." When you couple that upbeat outlook with Qualcomm's still-reasonable forward P/E of 14, it's tough to disagree with Northland's bullishness.