There has been a lot of talk about how the market continues to make new highs and whether or not a correction is coming. Transportation stocks have been sending a warning signal — and that's making the Dow Theorists nervous.



Dow Theory, developed at the turn of the 20th century by Charles Dow, holds that, in order for the markets to be in a sustained uptrend or downtrend, both indexes — Industrials and transports — must confirm each other. When one of the indexes climbs to a new high (or falls to a new low), the other is expected to soon follow. "Soon" is the operative word here. Soon means shortly, in the near future, before long etc.