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 China Mobile (CHL) gained about 2% today after Goldman Sachs upgraded the Chinese telecom giant from neutral to conviction buy.

So what: Along with the two-notch upgrade, analyst Donald Lu planted a price target of $61 on the stock, representing about 23% worth of upside to Friday's close. So while contrarian traders might be turned off by China Mobile's price strength in recent weeks, Lu's call could reflect a sense on Wall Street that tailwinds from rapid LTE adoption give the company plenty of room to run.

Now what: According to Goldman, China Mobile's risk/reward trade-off is rather attractive at this point. "We expect strong 3G and LTE data growth to reverse CM's ARPU decline in 2015 (ex- VAT tax reform)," said Lu. "At SK Telecom and Verizon, two leading global LTE service providers, ARPU and EBITDA recovery after LTE launch resulted in significant share appreciation. We believe CM is in a similar position, and its potential ARPU and EBITDA rebound could drive a share price rerating." When you couple that upbeat outlook with China Mobile's rock-solid balance sheet and juicy 4% dividend yield, it's easy to understand Goldman's bullishness.