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 construction services company Jacobs Engineering Group Inc (NYSE:JEC) dropped as much as 11% today after it reported fiscal second-quarter earnings.

So what: Revenue fell 8.6% from a year ago and net income attributable to shareholders dropped 2% to $82.0 million, or $0.64 per share. Adjusted earnings per share were $0.72, which fell $0.06 below estimates, and revenue also fell short of expectations of $3.19 billion.  

To top it off, management said full-year earnings would be $2.90-$3.20 versus analyst estimates of $3.34 per share.

Now what: On the bright side, backlog increased 2.5% from a year ago to $8.9 billion, but most of those additional sales won't hit the books this fiscal year. But low energy and commodity prices are having a negative impact in the immediate term. Given the negative results right now, I think even paying 14 times the top end of this year's earnings is expensive, so I'll stay out of shares today.