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 NetScout Systems (NASDAQ:NTCT) rose by more than 20% during Thursday's intraday trading after the company announced significantly better-than-expected quarterly results.

So what: Adjusted quarterly revenue rose 9% to $92.2 million, which translated into non-GAAP earnings per share of $0.34. For reference, analysts on average were expecting earnings of just $0.30 per share on $88.89 million in sales.  

Now what: Those results were in line with the company's own expectations, which also lends credence to its reiterated fiscal full-year guidance for in-line adjusted net income per share of $1.40 to $1.50. In addition, NetScout reiterated its guidance for fiscal full-year non-GAAP revenue in the range of $385 million to $400 million, the midpoint of which also exceeds analysts' estimates for full-year revenue of $389.25 million.

NetScout has now beat expectations on both the top and bottom lines for each of the past three quarters, so it seems safe to say investors are finally taking note. Even after today's pop, and with shares currently trading at a reasonable 18 times next year's estimated earnings, the stock could prove a bargain for investors who buy now.

Fool contributor Steve Symington has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.