Transportation stocks dip, and that's a bad sign for the next few weeks

On Thursday March 7^th, the Dow Jones Transportation index declined for a 10th straight session.

It lost more than 4% in that time.

It was the longest such streak in a decade.

Since 1990, there have been only three other instances when the transports index had a losing streak of at least ten straight sessions (1994, 2000, 2009).

In the two weeks following all of those episodes, the index continued to trade sharply lower, according to a CNBC analysis of Kensho.

The average additional loss was more than 9 percent, much worse than the 4.4 percent that the S&P 500 lost on average during those weeks.