"If the Transport went up by seven percent every month for the next 12 months, then the Dow is going to be at, what? 23,000 ... which none of us expect," said Donald Broughton of Avondale Partners.
Broughton, who covers the transportation and industrial sectors, argued in a "Squawk Box" interview that the rally in Transports can't last, and that's because of the flow of goods being moved. "There's nothing out there other than those things related to e-commerce ... or those things related to fracking that are confirming it."
He added that truck tonnage, ocean intermodal containers, and car loadings in rail are all showing signs of weakness. "You're seeing less consumption. You're seeing less production. You're seeing less prosperity."
Year-to-date, the Dow Transports doubled the four percent gain in the Dow Jones Industrial Average, now at five-year highs.
As both major averages move up together, talk has heated up about Dow theory, which holds that the Industrials and Transports confirming each other's new highs can signal a breakout.
There's often a dispute among Dow theorists on when that breakout has happened. But Broughton said, "It's not that the stocks are somehow omniscient, they're a reflection of the underlying goods flow."
As for sectors within transportation, he said he's concerned about the truckers because of tight margins, but less worried about rail — particularly Union Pacific, which has benefited from fracking and chemical research.
Much of the rapid gain in Transports has come from airlines. Delta, for instance, is up 18 percent since the beginning of January.
—By CNBC's Matthew J. Belvedere; Follow him on Twitter