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 Chevron (NYSE:CVX) gained slightly this morning after Deutsche Bank initiated coverage on the oil and gas giant with a buy rating.

So what: Along with the upgrade, analyst Ryan Todd planted a price target of $142 on the stock, representing about 14% worth of upside to yesterday's close. So while contrarian traders might be turned off by Chevron's strong rebound in recent months, Todd's call could reflect a sense on Wall Street that the company's improvement prospects still aren't fully baked into the valuation.

Now what: According to Deutsche, Chevron's risk/reward trade-off is rather attractive at this point. "In some ways, Chevron is the standard bearer for Super Major dynamics in recent years: rapid spending growth driven by huge, capex-heavy projects, shrinking free cash flow, and disappointing growth," said Todd. "However, its strength remains its steady plan and clear identity: organically driven, deep, oil-levered, high-margin project queue, now complimented by possibly the highest quality US onshore position in the industry. The turn in capex/cash flow may still be 12 months out, but the coming inflection will drive leading growth (20% by 2017) and free cash flow (~6% in 2017) in the coming years." When you couple that upbeat outlook with Chevron's juicy dividend yield of 3.5% and cheapish forward P/E of 10, it's tough to disagree with Deutsche's bullishness.