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 (ACAS), a private equity and venture capital firm that specializes in buyouts and recapitalizations, dipped as much as 11% after the company reported weaker-than-expected fourth-quarter results.

So what: For the quarter, American Capital reported net operating income of $0.19 per share which was negatively affected by $0.05 "due to the net impact of debt and equity securities being added and removed from non-accrual status." By comparison, Wall Street had been forecasting net operating income of $0.24. Also hurting was a net unrealized depreciation of $237 million in its portfolio valuation, headlined by a $185 million unrealized depreciation in American Capital Asset Management. ACAM is projecting weaker management fees associated with managing two mortgage-REIT portfolios.

Now what: This would mark the fourth consecutive quarter that American Capital has missed Wall Street's projections by a mile. In addition, the mortgage-REIT market may only further weaken as the Federal Reserve begins to pare back its monthly economic stimulus known as QE3. Were this to happen, its subsidiary, ACAM, may run into even rougher waters. Following this report I would suggest sticking to the sidelines until we see clear signs of top-line improvement, because net asset value gains simply aren't enough in my view to justify a purchase here.