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 HVAC supplier AAON (NASDAQ:AAON) jumped 10% today after reporting earnings.

So what: First-quarter revenue was up 14.4% from a year ago to $76.4 million, easily topping the $69.2 million analysts expected. Earnings of $0.26 per share was also well in excess of the $0.17 target analysts had set.  

Now what: A bad winter hurt a lot of companies tied to the construction market, but playing both the heating and cooling side helped AAON. Management was a little less bullish on the rest of the year, saying only that "we expect 2014 to produce higher sales and earnings than 2013." Given strong growth in the first quarter, I'm taking a cautious approach after those comments, because with shares trading at 20 times next year's earnings estimates, this isn't a cheap stock if it isn't going to grow significantly.