The index is a running average of the stock prices of twenty transportation corporations, with each stock's price weighted to adjust for
stock splits and other factors. , the index consists of the following 20 companies: Alaska Air Group replaced
AMR Corporation on December 2, 2011, after AMR corp. filed for bankruptcy protection. Effective October 30, 2012, Kirby Corp. replaced
Overseas Shipholding Group, Inc. Effective October 1, 2014, Avis Budget Group Inc. replaced
GATX Corporation. On October 15, 2015, American Airlines Group replaced
Con-way. Effective December 14, 2021, Old Dominion Freight Line replaced
Kansas City Southern. Effective February 26, 2024, Uber replaced
JetBlue Airways. The index change was prompted by JetBlue’s low weight in the index of less than one-half of one percentage point caused by its low share price. ==History==