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 cyber security software specialist Sourcefire (NASDAQ:FIRE.DL) popped 12% today, after its quarterly results and guidance topped Wall Street expectations.

So what: Sourcefire shares have slumped in recent months on weak forecasts from rivals, but a strong third quarter -- adjusted EPS of $0.25 on revenue of $58.8 million versus the consensus of $0.21 and $55.8 million -- coupled with upbeat guidance for the full year, rekindles optimism over the trends working in its favor. Internet data leaks continue to drive strong demand from both its government and enterprise clients, giving investors plenty of good vibes over growth going forward.

Now what: Management now sees full-year adjusted EPS of $0.80-$0.82 on revenue of $217.7 million-$219.7 million, while Wall Street was expecting adjusted EPS of only $0.76. According to interim CEO Marty Roesch:

Our threat centric approach addresses the full attack continuum and drives our innovation, resulting in more effective protection for our customers. This, combined with the investments we are making in our go-to-market strategy, is enabling us to achieve significant levels of growth.

With the stock now up more than 60% from its 52-week lows, and trading at a lofty forward P/E of about 50, however, much of that growth might already be baked into the price.

Interested in more info on Sourcefire? Add it to your watchlist.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.