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 Fortinet (FTNT 1.00%) have skyrocketed today by as much as 25% after the network security specialist reported fourth-quarter earnings.

So what: Revenue during the quarter totaled $151.2 million, a 25% gain from a year ago. Non-GAAP earnings per share came in at $0.17. Both revenue and adjusted earnings results topped analyst forecasts, which would have been happy with $144.3 million in sales and a profit of $0.15 per share.

Now what: Topping off the figures, Fortinet also issued strong guidance for the upcoming year, predicting revenue in the range of $625 million to $635 million. That was ahead of Street forecasts of just $618.9 million. Nomura Securities has boosted its estimates on shares, increasing its price target from $24 to $26 on the strong outlook and expectation that growth will be sustainable.

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