Market investigations in the UK have a rich history of uncovering consumer harm and inefficiencies in sectors like groceries, energy, retail banking, and funeral services. These investigations, distinct from traditional competition laws, allow for the imposition of market-wide remedies to address market failures not caused by anti-competitive behavior. They play a crucial role in promoting competition, protecting consumers, and fostering economic growth by improving market efficiency. The upcoming introduction of new legislation for ex ante regulation in digital markets will further enhance the tools available to address market power and promote competition and innovation. Businesses, even if not engaged in unlawful activities, may still face costly and reputation-damaging investigations, highlighting the importance for competition law advisors to understand the implications of market investigations and the power to impose remedies.