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: Sometimes, life just doesn't seem fair. Shareholders of air-cargo hauler Atlas Air Worldwide (Nasdaq: AAWW) awoke to a 10% pop in price on their stock this morning -- a gain that proved as thrilling as it was ephemeral. By day's end, the massive selloff elsewhere in the market had wiped out almost the entire gain. But did Atlas deserve to fall alongside everyone else?

So what: Atlas reported $0.90 in per-share profits for the second quarter, down 28% from last year's Q2 -- but a good eight cents more than analysts had expected to see. That's the good news. The bad news is that despite earning more than expected in Q2, management admitted that it will end the year earning less  than expected -- just $5 a share, which is less than both the Street, and Atlas itself, had previously predicted.

Now what: Of course, even $5 a share (if it gets there) is going to give Atlas a P/E ratio of about 10 by year's end. Assuming Wall Street leaves its long-term estimates unchanged, and Atlas can achieve the 12% long-term growth it's pegged for, then the stock doesn't seem especially richly priced. My guess: The share-price gains Atlas had, and lost, may come home to roost once again.

Don't miss a word of Fool news on Atlas Air: Add the stock to your Fool Watchlist now.

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.