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: Athenahealth (Nasdaq: ATHN) shares jumped 23% in trading early Friday on positive third-quarter earnings.

So what: Athenahealth earned $0.18 per share in the quarter, higher than the $0.13 estimated by analysts. With 34% of shares sold short, it appears a short squeeze is magnifying the move upward.

Now what: The market has been visibly bearish on Athenahealth considering the huge short interest. This is two consecutive quarters the company has beaten estimates, which is always a plus, but I'm wary of buying on a short-squeeze spike. This Fool will sit out this spike and watch for a better opportunity.

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