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: China Yuchai International (NYSE: CYD) dropped 10% in intraday trading today after an analyst made cautious comments about the stock in a research report.

So what: After touring a China Yuchai facility in southern China, Piper Jaffray expressed concern about the company's ownership structure and about truck demand in the second half of 2011. Piper Jaffray has a "neutral" rating on the stock, which many investors interpret as a recommendation to sell.

Now what: Piper also noted that it came away from its tour believing China Yuchai "is head-and-shoulders above the rest of our US-listed Chinese stocks when it comes to brand recognition and customer acceptance." Nonetheless, news about slowing economic growth -- including in fast-growing China -- can't be helping the stock. Nor can recent concerns about the reliability of financial statements from companies based in China.

Interested in more info on CYD? 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.