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 Chinese real estate Internet portal SouFun (NYSE: SFUN) aren't having so much fun today, down by as much as 13%, after the company reported fourth-quarter earnings.

So what: Revenue rose 15% to $113.9 million, with earnings per share turning out to be $0.49. The top line beat the market's expectations while the bottom line fell short by a nickel. Full-year revenue jumped 53% to $343.8 million.

Now what: What's really weighing on shareholders is the relatively soft guidance that SouFun issued. The company sees fiscal 2012 sales between $380 million and $400 million, while the Street was looking for $412.6 million on average. Add in the overall pessimism in the broader market today and you get a recipe for a mean sell-off.

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

Fool contributor Evan Niu holds no position in any company mentioned. Click here to see his holdings and a short bio. 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. The Motley Fool has a disclosure policy.