Transport stocks have long been a leading indicator for equity bulls and, in spite of surging oil prices, this bellwether sector has charged ahead in recent weeks.

One of the tenets of Dow Theory is that a bullish or bearish trend for the Dow Jones Industrial Average is flagged whenever the Dow Transportation Average rallies or declines sharply. This is based on the notion that transport stocks reflect the underlying economy far better than the average company and thus foreshadow prospects for economic growth.