On April 30, 2018, Marathon Petroleum announced its acquisition of the newly formed Andeavor making Marathon the largest refiner in the U.S. (by capacity) and one of the top five refiners in the world. The merger is moving into its final stages, and Marathon’s CEO is positive about the combination of the two well situated companies. In this post, we analyze the recent acquisition history of Western Refining, Tesoro, and Marathon, which has started to look somewhat like nesting dolls of acquisitions.