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 China-based human-resources specialist 51job (Nasdaq: JOBS) went to work today with an intraday gain of 18.2% in its sights, all on very heavy trading volume.

So what: A tremendous first-quarter report showed 20% higher earnings than the Street had expected on a 27% year-over-year revenue boost. One analyst firm upgraded 51job on the news while another issued a downgrade, but it's investors who set share prices in the end.

Now what: The Chinese equivalent of Monster Worldwide (NYSE: MWW) and Dice Holdings (NYSE: DHX) is treating its investors like royalty by more than tripling over the past year. The company's tea leaves tell me that the Chinese economy remains healthy and growing. The fact that analysts are underestimating the company points to a rash of potentially undervalued stocks that depend directly on a booming Chinese middle class.

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