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 FirstEnergy (NYSE:FE) climbed 1% today after the Jefferies Group upgraded the diversified energy company from underperform to hold.

So what: Along with the upgrade, analyst Paul Fremont raised his price target on the shares to $36.50 (from $33.50), pretty much exactly where the stock closed on Monday. FirstEnergy shares have been crushed over the past several months on cost issues and increased environmental regulation, but Fremont believes the risks are now largely baked into the price, providing investors with at least some margin of safety.

Now what: In Jefferies' opinion, management has taken the appropriate steps to stabilize the business. "The stock has underperformed the UTY by 11.8% since we downgraded the stock in January,"Jefferies said. "Moody's concerns regarding FE competitive businesses have been resolved with the company raising $1.5 billion in proceeds from the Harrison asset transfer proceeding and the sale of hydro assets." More important, with FirstEnergy shares still off about 20% from their 52-week highs and boasting a juicy dividend yield of 6%, there might even be room to benefit from that derisking.