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: After an 11% drop in share price, Coach (NYSE: COH) were looking just a little less luxe Thursday.

So what: Yet the catalyst for the day's sell-off seems tenuous in the extreme. Last week, a report on Chinese manufacturing showed contraction for the third month in a row. This in turn has pundits talking of a "cooling off" of China's red-hot growth pace, with a likely slowdown in middle-class consumer spending resulting as the country as a whole becomes less affluent.

Now what: As you can see, there's not a lot of hard numbers behind these theories so far. Barely even a direct connection between last week's report and this week's worries about how it might affect Coach, Tiffany (NYSE: TIF), and other luxury brands. Then again, with Coach shares trading for a lofty 18.5 times multiple to trailing earnings (and pegged for only 13.6% long-term growth) any hint of a slowdown -- even a slowdown that might happen sometime in the future -- may serve as an excuse for cashing in profits and selling off the shares.

Hmm. Did I say "may serve?" In fact, I think it just did.

Are investors overreacting to Middle Kingdom rumor-mongering? Will Coach regain its cachet? Add the stock to your Fool Watchlist, and find out.