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 defense supplier Esterline Technologies (NYSE: ESL) sank as much as 11%, before finishing the day down 6%. A revised outlook in its preliminary earnings report appears to be the culprit.

So what: The company scaled back adjusted EPS guidance for the fiscal year, from $5.10-$5.25 to $4.87 to $5.00, blaming lower production of aircraft, such as the Hawker Beechcraft T-6B Trainer and the Airbus A380, as well as F-35 inventory rebalancing at Lockheed Martin (NYSE: LHM). The company also took a $52 million non-cash goodwill impairment charge for its Racal Acoustics defense business.

Now what: CEO Brad Lawrence said the slowdown causing the revised guidance was a temporary issue, and expressed confidence that his company’s "solid market positions optimize its ability to seize opportunities" as they arise. Defense is a notoriously cyclical industry, so investors shouldn’t be surprised to see speed bumps like this from time to time, but this shouldn’t change your overall investing thesis. A 6% haircut seems deserved considering the cut in projections.

Want to stay connected with Esterline? Just click on the link to add Esterline Technologies to your watchlist.