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: Sonus Networks (Nasdaq: SONS) popped 29% in intraday trading today after delivering better-than-expected fourth-quarter earnings and 2011 guidance.

So what: Profits have been a sometimes thing for Sonus, and it badly missed consensus EPS estimates in the third quarter. Revenue in the fourth quarter grew 21% from the year-ago quarter, a huge surprise compared to the consensus forecast of essentially flat revenue.

Now what: Guidance for 2011 calls for revenue growth of 6% to 14% and suggests the year could be slightly profitable on a GAAP and non-GAAP basis. A stronger product portfolio is driving both the recent growth and management's confidence in the coming year. That said, guidance does not give any reason to suggest 2011 EPS will come close to justifying the current stock price.

Interested in more info on SONS? Add it to your watchlist by clicking here.

Fool contributor Cindy Johnson does not own shares of any company named above. 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 has a disclosure policy.