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 engineering contractor Ducommun (NYSE:DCO) fell 17% today after the company reported disappointing earnings.

So what: Sales fell 1.5% to $181.3 million in the quarter, while net income dropped from $5.1 million to $4.6 million, or $0.42 per share. Both figures were short of estimates, with earnings falling a nickel below expectations.  

Now what: Management said the non-aerospace and defense business is what hurt results, declining 25%. The good news is that that's a pretty small portion of the company's revenue, hence the 1.5% decline in revenue overall. However, I don't see a lot of improvement across the company's other businesses, which will keep me out of the stock today. For 15 times trailing earnings I expect a little more than declining earnings and bottom line results.

Fool contributor Travis Hoium 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.