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 thermal imaging systems maker FLIR Systems (Nasdaq: FLIR) fell as much as 13% after the company announced preliminary second-quarter results.

So what: FLIR expects revenue of about $390 million and earnings per share of $0.18, or $0.35 after adjustments for one-time items in the second quarter. That fell short of expectations of $0.37 from analysts and brought a downgrade to market perform from outperform from Morgan Keegan analysts.

Now what: Weakness in the defense market is slowly taking its toll on suppliers, and FLIR is the latest to get hit. Shares aren't terribly expensive at 14.4 times forward P/E, but with defense spending likely to continue to come under pressure, I would be cautious buying here. Without any catalysts in the future, I would like to see if momentum continues downward in the next week before buying shares of FLIR.

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

Fool contributor Travis Hoium does not have a position in any company mentioned. You can follow Travis on Twitter at @FlushDrawFool, check out his personal stock holdings or follow his CAPS picks at TMFFlushDraw.

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