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 Jabil Circuit (NYSE: JBL) short-circuited today, down by as much as 10%, after the company reported earnings yesterday.

So what: Revenue was $4.3 billion, roughly flat with the year-ago quarter, and adjusted earnings per share was $0.54. Those results were slightly worse than the market was expecting on revenue, but the bottom line fell short by about $0.04 per share. Jabil Circuit also guided next quarter below consensus estimates.

Now what: The coming quarter should see sales in the range of $4.3 billion to $4.5 billion, with earnings per share between $0.51 and $0.62. Analysts were calling for $4.52 billion in revenue and a $0.67 per share profit. Jabil Circuit is running into shrinking margins related to providing the aluminum casing in Apple's (Nasdaq: AAPL) iPhone 5, since Apple is one of its biggest customers. The new smartphone is ramping up production to meet demand, causing negative pressure on Jabil Circuit's results.

Interested in more info on Jabil Circuit? Add it to your watchlist by clicking here.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.