This class action centers on allegations that several major U.S. airlines—Delta, Southwest, United (and its predecessor Continental), US Airways, and American—worked to keep domestic ticket prices artificially high during a period when air travel was rapidly consolidating and “capacity discipline” became an industry buzzword. The settlement applies to people who purchased domestic airline tickets in the covered windows (generally July 1, 2011 through December 2017, and through June 14, 2018 for American), reflecting claims that competition may have been muted not by explicit collusion on a single fare, but by coordinated limits on seat supply that can push prices upward even when demand fluctuates. In airline markets, where fares are heavily driven by available capacity and route-by-route competition, even subtle, industry-wide shifts in how much airlines choose to fly can meaningfully affect what consumers pay. The lawsuit was filed under U.S. antitrust laws (including the Sherman Act) on the theory that the airlines unlawfully agreed—directly or indirectly—to restrain competition by limiting capacity growth, resulting in higher fares for consumers. Its significance lies in how it targets a form of alleged price fixing that can operate through parallel conduct and signaling (e.g., public statements, earnings calls, or industry meetings) rather than a simple “we set the same price” agreement, a recurring issue in modern antitrust enforcement. Similar theories have appeared in other sectors where a small number of large players dominate and can more easily align incentives—such as shipping, packaged goods, and technology marketplaces—raising broader questions about how regulators and courts should treat concentrated industries, what kinds of communications cross the line into coordination, and how consumer harm is measured when the alleged conduct involves managing supply rather than posting identical prices.