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 network equipment specialist F5 Networks (Nasdaq: FFIV) jumped as high as 14% in intraday trading after its quarterly results and outlook topped analyst estimates.

So what: The demand for F5's products -- especially from providers servicing the booming mobile market -- was obviously stronger than Mr. Market expected. F5 posted a fourth-quarter profit of $63.9 million, or $0.79 a share, which was nicely above the average analyst estimate of $0.72 a share.

Now what: With management also issuing upside guidance for next quarter, F5's short-term picture looks particularly bright. But while business should continue benefitting from the trend towards data center consolidation and cloud computing, shareholders might not be able to at these valuation levels. With the stock having more than doubled over the past year and sporting a lofty P/E of about 55, Fools would do well to play those trends with bigger, stronger, and, most importantly, cheaper rivals like Cisco Systems (Nasdaq: CSCO) or Brocade (Nasdaq: BRCD).

Interested in more info on F5? Add it to your watchlist by clicking here.

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Try any of our Foolish newsletter services free for 30 days.

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