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 power systems maker Generac Holdings (NYSE:GNRC) jumped 15% today after the company released third-quarter earnings.

So what: Revenue rose 20.9% from a year ago to $363.3 million, easily topping estimates of $342.31 million from Wall Street. Net income rose 85% to $47.1 million and, after adjusting for one-time items, earnings per share were $1.06 versus a $0.79 estimate.  

Now what: This was a resounding earnings beat all around and even full-year revenue guidance was increased to show net sales jumping in the low-to-mid 20% range over the prior year. Management said that national account customers are driving growth and that new products will help drive growth going forward. Shares still trade at just 13 times next year's estimates, so considering the revenue growth and stock price I think this is still a good buy even after today's pop. 

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Fool contributor Travis Hoium has no position in any stocks mentioned. The Motley Fool owns shares of Generac Holdings. 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.