High fuel prices, eventually, can hit transportation companies' earnings even if they typically pass costs through to customers.

Chief Financial Officer Frad Delco at J.B. Hunt Transport Services told investors at a Morgan Stanley conference that third-quarter earnings would be down from the second quarter.

"There is a little bit of a mismatch, based upon the delay part of pricing, that we see in intermodal relative to the costs we're feeling now," said Delco. "We want to be transparent with investors and give an update that, in light of these costs that are sort of hitting us, we are expecting our Q2 to Q3 earnings to actually drop 5% to 10%-sorry to give you a range."

J.B. Hunt doesn't typically provide explicit financial guidance. But the company is experiencing "some of the most radical and abnormal swings in fuel prices" ever, Delco said Tuesday at the conference. Diesel prices are north of $6 per gallon, up from about $3.70 a year ago.

Wall Street was projecting third-quarter earnings per share of $2.09, up from $1.76 a year ago. Guidance implies third-quarter earnings per share will be closer to $1.77, roughly flat year over year.

Shares of the shipper were down 11% in premarket trading at $243, while S&P 500 futures were up 0.2%.

Coming into Wednesday, shares have gained 41% this year, with investors encouraged by earnings growth after a few lean years. J.B. Hunt earned more than $9 a share in 2022. It earned about $6 a share in 2025. Wall Street expects 2026 earnings of about $7.75, according to FactSet.

To be sure, the cost increases might work themselves out over time. Still, high diesel prices could be impacting shipping demand, which is a watch item for the entire sector.