One of the earliest investment theories of Wall Street remains to be confirmed.

For investors acclaiming stocks at record levels, a clbadic secular theory says the market is not out of the woods yet.

The so-called Dow Theory, developed in the early 1900s by Charles Dow and still used for religious purposes by many Wall Street gamblers, claims that a true bullish escape is confirmed when the Dow Jones Industrial Average and the Dow Jones Transportation Average are simultaneously reaching new heights.

At the moment, the Dow Jones Industrial Average continues to reach new heights (including Tuesday) after breaking the 27,000 mark last week. However, the transport gauge remains close to 7% below its September record. In other words, Dow's theory has not confirmed the current rally.

"To be optimistic, Dow Theory needs a new record for DJTA," said Ed Yardeni, chief investment strategist at Yardeni Research, in a note on Tuesday. "The DJTA has not yet confirmed the record strength of the DJIA, according to Dow Theory supporters, who would be more optimistic if the DJTA also moved into record territory."

Investors believe that transport actions are a barometer of global economic activity and that a recovery without their support can not be sustainable. The global economy is slowing down because of the trade war between the United States and China.

The group has a big day on Tuesday, boosted by trucking and shipping company J.B. Hunt, who jumped more than 6% on earnings above expectations. Canadian Pacific also rose nearly 3% on strong second-quarter numbers.

The Dow Jones Transportation Average is up 18% this year and at the same pace as its seventh consecutive weekly gain for the first time since 2016, but is expected to exceed its record of 2018 for Dow Theory members.

The shares resumed their return this year after the US Federal Reserve announced an easier policy to support the economy during a global downturn. The Dow is up more than 17% while the S & P 500 has risen more than 20% since the beginning of the year. Traders are banking on a 100% probability of a Fed rate cut later this month, which would help extend the record uptrend.

The underperformance of the transportation group stems mainly from the weakness of the air cargo and logistics sector, which remains more than 20% below its January 2018 peak, Yardeni said.

Only one means of transportation could help or hinder the cause later on Tuesday. CSX Corp reports after the bell.