The Dow Jones Transportation Average (DJTA, also called the "Dow Jones Transports") is a U.S. stock market index from S&P Dow Jones Indices of the transportation sector, and is the most widely recognized gauge of the American transportation sector. It is the oldest stock index still in use, even older than its better-known relative, the Dow Jones Industrial Average (DJIA). Components 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. As a result, it can change at any time the markets are open. The figure mentioned in news reports is usually the figure derived from the prices at the close of the market for the day. Changes in the index's composition are rare, and generally occur only after corporate acquisitions or other dramatic shifts in a component's core business. Should such an event require that one component be replaced, the entire index is reviewed. , 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. History The average was created on July 3, 1884, by Charles Dow, co-founder of Dow Jones & Company, as part of the "Customer's Afternoon Letter". At its inception, it consisted of eleven transportation companies—nine railroads and two non-rail companies: Chicago, Milwaukee and St. Paul Railway Chicago and North Western Railway Delaware, Lackawanna and Western Railroad Lake Shore and Michigan Southern Railway Louisville and Nashville Railroad Missouri Pacific Railway New York Central Railroad Northern Pacific Railroad preferred stock Pacific Mail Steamship Company (not a railroad) Union Pacific Railway Western Union (not a railroad) As a result of the dominating presence of railroads, the Transportation Average was often referred to as "rails" in financial discussions in the early and middle part of the 20th century. Use in Dow theory The Transportation Average is an important factor in Dow theory. Price history In 1964, the index first broke 200, slightly over where it was in 1929. In 1983, the index first broke 500. In 1987, the index broke 1000. It closed at