This article considers, with reference to recent cases, the approach of the Competition and Markets Authority in investigating mergers in dynamic markets. It examines the CMA's jurisdictional and substantive tools, sources of evidence, the use of counterfactuals, the assessment of when a merger may result in a substantial lessening of competition and appropriate remedies. The article concludes with a brief discussion on whether existing merger control tools are likely to be sufficient to ensure that merger control is able to continue to adequately protect consumers in dynamic markets in the future.