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: Commercial transportation specialist Forward Air (Nasdaq: FWRD) was spinning its wheels today, dropping 11% today after management cut third-quarter guidance.

So what: The quarterly forecast was cut sharply, down from a range of $0.47 to $0.51 a share to a range of $0.39 to $0.41, well below the average estimate of $0.49. CEO Bruce Campbell said the quarter had started off strongly but that airport-to-airport tonnage began to decrease in August. A rate increase imposed on September also failed to deliver the results he had expected.

Now what: Forward Air's announcement echoes Fed Ex's (NYSE: FDX) decision last week to cut its full-year outlook by about 10%, as the shipping king said the global economy is slowing. Caterpillar (NYSE: CAT), another bellwether for the global economy, also sent negative signals yesterday. With management making this announcement right as the quarter is ending, investors may want to play it cool. If the heavyweights are right about the cooling of the economy, Forward Air could be forced to cut guidance again in Q4. Right now, analysts are calling for $0.58 a share in the last three months of the year.

For more information on Forward Air, just add the company to your Watchlist.

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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.