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 wealth manager Noah Holdings (NYSE: NOAH) fell as much as 10.4% on heavy trading today, starting with a massive-volume downward spike right at the opening bell.

So what: The move mirrors a 17% upward spike last Friday and a plethora of temporary intraday jumps and falls that could drive a nervous man to distraction. Noah shares tend to amplify what's going on in the financial services sector, and today, American peers Legg Mason (NYSE: LM) and Artio Global Investors (NYSE: ART) are sagging badly based on European economy concerns.

Now what: On top of general market concerns, the U.S. Senate just introduced a bill that could take American money out of the Chinese market -- not much help for a Shanghai-based wealth manager. Noah has potential, but needs to have some of the volatility-boosting uncertainty shaken out of it first. Trading at nearly 26 times trailing earnings, this is one of the most expensive stocks in the financial services sector -- on any continent.

Interested in more information about Noah Holdings? Add it to My Watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. 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 is investors writing for investors.