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 Canadian Solar (NASDAQ:CSIQ) rallied as high as 4.7% on Monday after FBR Capital upgraded the solar products specialist from market perform to outperform.

So what: Along with the upgrade, analyst Aditya Satghare reiterated his price target of $40 on the stock, representing about 30% worth of upside to Thursday's close. So while momentum traders might be turned off by Canadian Solar's year-to-date price weakness, Satghare's call could reflect a sense on Wall Street that its growth prospects are becoming too cheap to pass up.

Now what: According to FBR, Canadian Solar's risk/reward trade-off is rather attractive at this point. "We upgrade Canadian Solar (CSIQ) to Outperform from Market Perform and maintain our $40 price target, based on our view that the current stock price gives little benefit for the cash flow generation from the company's diverse project pipeline beyond the project buildout in Canada," Satghare said. "Within the China complex, we see Canadian Solar as having built one of the best global project development businesses and pipelines, and markets such as Japan and China offer multiple opportunities to monetize this pipeline in the future." Given FBR's solid stock-picking track record -- currently ranked in the top 10% of our CAPS community -- less risk-averse Fools might want to take a closer look at Canadian Solar.