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 American Capital (Nasdaq: ACAS) soared as much as 11% on heavy volume when the investment firm reported strong fourth-quarter results and a positive 2011 outlook.

So what: Not long ago, American Capital was considered a candidate for bankruptcy. No longer. Last night, the firm, which provides debt financing to growing middle market companies, reported $0.19 in per-share earnings on $143 million in operating income. Analysts were expecting $0.17 and $140.86 million, respectively.

Now what: Many Fools saw this coming. So did insiders. CEO Malon Wilkus had been a buyer of his company's shares in September, when they were still trading for $5.88 a share. (Insiders still own 2.09% of the business despite an increase in planned 10b5-1 sales since December.)

The stock is less of a bargain today but still trades for 12% below American Capital's $10.71 in net asset value per share. I'm a buyer right up to the point when the share price exceeds NAV, which could be later this year.

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Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team. He didn't own shares in any of the companies mentioned in this article at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. You can also get his insights delivered directly to your RSS reader. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is also on Twitter as @TheMotleyFool. Its disclosure policy is at least 10% better than other disclosure policies.