This book provides an in-depth exploration of the Digital Markets Act (DMA).With an ensemble of contributors who have been involved in major antitrust cases that shaped the legislative text, the book explains the rationale for the DMA, introduces the reader to the digital services falling within its scope, sets out the process for 'gatekeeper' designation, and provides insights into the interpretation issues and enforcement challenges that arise from the obligations it establishes. Analysing the DMA in the broader legal and market context, the chapters examine tensions between the DMA and other (EU and national) rules governing the conduct of online platforms, compare the DMA to similar initiatives undertaken in other jurisdictions, and bring perspectives from other disciplines, such as data protection regulation. A companion website reports on important developments in relation to the DMA, such as the decisions designating tech giants as gatekeepers and subsequent litigation arising therefrom, and provides links to analysis discussing the developments. An authoritative treatment of the DMA is paired with an easy-to-follow writing style to make this comprehensive compendium essential reading for practitioners, judges, regulators, and researchers working on matters relating to the digital economy.