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 Bankrate (NYSE:RATE) plunged nearly 23% during intraday trading Thursday after the company reported disappointing quarterly earnings results, and announced its CEO would resign.

So what: Quarterly revenue came in at $121.2 million, which translated to adjusted net income of $13.5 million, or $0.13 per share. On a GAAP basis, Bankrate lost $7.8 million, or $0.08 per share. For reference, analysts were expecting higher non-GAAP earnings of $0.15 per share on lower sales of $119.7 million.

Worse yet, the company added to uncertainty by announcing its 10-year CEO Thomas Evans will step down from his post and from the company's board of directors at the end of 2013. Evans will be replaced by Bankrate's current chief operating officer, Kenneth Esterow, beginning January 1, 2014.

Now what: The announcements sparked at least one downgrade from buy, to hold, by analysts at Stifel, who were modeling slightly higher revenue for the quarter. They also cited the stock's valuation and expressed worries centering around its CEO transition.

Even if Bankrate can manage to return to sustained profitability, shares still look expensive at nearly 24 times next year's estimated earnings, and 29 times the company's current $59 million in real annual free cash flow. As it stands, I can't blame skittish investors for bowing out today.

Fool contributor Steve Symington has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. 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. The Motley Fool has a disclosure policy.