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 Qiwi PLC (QIWI 9.88%) rallied more than 3% today after Deutsche Bank initiated coverage on the Russian online payment systems company with a buy rating.

So what: Along with the bullish call, analyst Bob Kommers planted a price target of $60 on the stock, representing about 43% worth of upside to Friday's close. So while momentum traders might be turned off by Qiwi's price weakness in recent weeks, Kommers' call could reflect a sense on Wall Street that its growth prospects are just too cheap to pass up.

Now what: According to Deutsche, Qiwi's risk/reward trade-off is rather attractive at this point. "We expect Qiwi to be a winner in the Russian epayment market, benefiting from the shift from offline retail sales and bank transactions to online payments and money transfers," said Kommers. "Market share gains in the loan repayment, remittance and e-commerce markets should spur a 31% CAGR in (USD) EPS in 2013-16E." When you couple that upbeat outlook with Qiwi's PEG of 0.8, it's tough to disagree with Deutsche's bullishness.