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 Cliffs Natural Resources (CLF -11.03%) gained 3% today after Cowen upgraded the iron ore miner from underperform to market perform.

So what: Along with the upgrade, analyst Anthony Rizzuto, Jr. boosted his price target to $20 (from $11), representing about 11% worth of downside to yesterday's close. While momentum investors might be turned off by the stock's big plunge over the past year, Rizzuto believes that the downside might now be limited given a few positive events that are likely to unfold in Cliffs' not-so-distant future.

Now what: According to Cowen, Cliffs' operations have plenty of room to improve. "We have identified several potential catalysts that could have positive implications for Cliffs Natural Resources," noted Cowen. "In our view, the most important being the possible structural changes that may be implemented by a new management team." More important, with the stock still off a whopping 50% from its 52-week highs, Cliffs' downside might be limited enough to make betting on those catalysts a particularly savvy move.