Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of student loan giant SLM (NYSE: SLM) -- better known as Sallie Mae -- were given an A+ by investors today, who sent them shooting up 17% after the company announced first-quarter results.

So what: While SLM may sometimes find itself uncomfortably lumped with the hapless Fannie Mae (OTC BB: FNMA.OB) and Freddie Mac (OTC BB: FMCC.OB), the company gave investors a reminder today of just how much better its business is doing. For the first quarter, Sallie Mae reported $260 million in "core earnings" or $0.48 in core earnings per share. That's up from $215 million in the first quarter of last year and ahead of the $0.40 that Wall Street had expected. In an apparent sign of financial strength, Sallie Mae also reinstated a quarterly dividend and authorized $300 million in share buybacks.

Now what: And as if all of that wasn't enough, the company also projected full-year earnings per share of $1.70, which is ahead of the $1.67 that analysts had been estimating. If we're to believe management, then SLM's stock is trading at less than 10 times 2011 earnings. Of course while that sounds pretty darn cheap, the stock appears to have a ways to go to get back into investors' good graces -- currently it carries a rating of just two stars in The Motley Fool's CAPS community. And that's not totally without reason -- the company currently has a leverage ratio (total assets-to-shareholders' equity) of nearly 40, which is enough to keep even risk-tolerant investors tossing and turning at night.

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Fool contributor Matt Koppenheffer does not have a financial interest in any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy prefers dividends over a sharp stick in the eye.