The Dow Transportation Average settled at a new record high during Tuesday's trading session, after rising 15 percent in the past two months.
The average, which lagged other major indices in 2012, is now leading the gainers in 2013, up more than 6 percent, compared to a 3 percent increase for the S&P 500 index , the Dow Jones Industrial Average, and the Nasdaq Composite Index.
Back in Oct. 17, CNBC's "By the Numbers" blog ran a story showing how the spread between the Dow industrial average and the Dow transports reached its widest point in six years. Historically, the spread between the two did not stay apart for long.
Delta Air Lines, Union Pacific, and FedEx are some of the names that have driven the average higher in the past two months.