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 medical clinic billings and records software specialist athenahealth (Nasdaq: ATHN) surged 14% today after its quarterly results and full-year profit outlook topped Wall Street expectations.

So what: Thanks in large part to strong physician additions, athenahealth posted second-quarter adjusted earnings of $0.22 per share, versus the average analyst estimate of $0.19 per share. The shares are touching new 52-week highs on the market-beating report, so it's clear that investors fully expect athenahealth's positive sales trend -- particularly from its business services segment -- to continue.

Now what: I'd be cautious about riding this recent wave of momentum. Given today's double-digit rally, the shares are now up 150% over the past year and trade at a rather unsettling forward P/E of 51. With main rivals Allscripts Healthcare (Nasdaq: MDRX) and McKesson (NYSE: MCK) available at far cheaper prices, athena doesn't seem like the healthiest bet at this point.  

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Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Motley Fool newsletter services have recommended buying shares of McKesson. Try any of our Foolish newsletter services free for 30 days.

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