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 restaurant reservation expert OpenTable (Nasdaq: OPEN) shot up more than 17% in intraday trading as third-quarter results came in well ahead of estimates.

So what: Non-GAAP earnings per share -- which for OpenTable basically means ignoring stock compensation expenses -- clocked in at $0.23 for the quarter, which was a trouncing of the $0.15 that Wall Street expected. And the sheer growth in the financials was nothing short of staggering. Year over year, revenue was up 44% and GAAP net income leapt more than 300%. No wonder investors are giving the company a pat on the back today.

Now what: My fellow Fool Rick Munarriz took CNBC's Herb Greenberg to task for doubting OpenTable prior to the quarter and said the company is "the real deal." While it's certainly tough to argue with smoking-hot results such as these, I think the stock may be a little too hot to handle at this point. Shares have nearly tripled since a year ago. The stock trades at roughly 77 times analysts' expected 2011 earnings. As Rick pointed out, earnings estimates keep right on rising with the company's success (thus bringing down the valuation ratio), but this Fool finds that less expensive stocks not only tend to lead to good returns, but also fewer ulcers.

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OpenTable is a Motley Fool Rule Breakers recommendation.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.

Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy assures you no Wookiees were harmed in the making of this article.