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 health insurer Aetna (NYSE: AET) were looking particularly healthy today as they climbed as much as 15% in intraday trading.

So what: Aetna posted fourth-quarter operating earnings today of $0.63, which edged out the $0.62 that Wall Street had expected. The profit, which includes adjustments for certain transactions and restructuring charges, was a 58% gain over last year's fourth quarter. The gain was driven in large part by lower expenses, including a lower medical benefit ratio, and was also helped by a lower share count. Revenue also topped analyst estimates, though it fell 2.5% from last year as membership in the company's programs declined.

Now what: It seems pretty unlikely that investors got too fired up about a $0.01 earnings beat. Instead, the excitement probably has more to do with the company's 2011 guidance and its dividend announcement. For 2011, Aetna expects to report between $3.70 and $3.80 in per-share operating earnings, which is well above the average analyst estimate of $3.65. Meanwhile, the company showed confidence in its business -- and matched a move by competitor Unitedhealth (NYSE: UNH) last year -- by announcing a quarterly dividend of $0.15. While the 1.7% yield won't wow many dividend investors, it's a big jump from the company's previous $0.04-per-year payout.

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UnitedHealth Group is a Motley Fool Inside Value pick. UnitedHealth Group is a Motley Fool Stock Advisor choice. Motley Fool Options has recommended a diagonal call position on UnitedHealth Group. The Fool owns shares of UnitedHealth Group. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

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