Editor’s note: This is an educational explainer about how the UK’s market abuse framework generally works. It is general information, not investment advice, and does not describe any specific current event, company, or security.
Ask most people what “market abuse” means and they will describe a version of the same scene: an executive learns confidential news before it becomes public, buys shares ahead of the announcement, and profits when the price moves. That scenario, insider dealing, is real and illegal. But it is only one branch of a much broader regime. The UK’s Market Abuse Regulation, known as UK MAR, prohibits an entire category of conduct that has nothing to do with secret information at all, including some behaviour that never involves trading a single share. Understanding where the boundary actually sits explains why compliance teams at banks, brokers, and even ordinary companies spend so much time on rules that go far beyond “don’t trade on tips.”
Three offences, not one
UK MAR, which took effect in 2016 and was carried into UK domestic law after Brexit with oversight from the Financial Conduct Authority, defines market abuse as covering three distinct offences. The first is insider dealing: using inside information, meaning specific, non-public information that would likely have a significant effect on price if disclosed, to deal or attempt to deal in a related financial instrument. The second is unlawful disclosure, which criminalises passing that inside information to another person outside the normal course of employment, profession, or duties, regardless of whether that person ever trades on it. The third, and the one that most clearly separates UK MAR from a narrow insider-trading statute, is market manipulation.
Market manipulation does not require any inside information whatsoever. It covers conduct such as giving false or misleading signals about the supply, demand, or price of a financial instrument, entering into transactions that secure the price at an abnormal or artificial level, or disseminating information through the media, including online forums and social platforms, that gives false or misleading signals while the person disseminating it knew or ought to have known the information was false. A trader who places and then rapidly cancels large orders purely to create a false impression of demand, without ever intending to complete the trades, is engaging in manipulation even though no confidential information changed hands. The same applies to someone who talks up or talks down a security in a public forum for personal gain while concealing that motive.
Where the regulation reaches
Another feature that distinguishes UK MAR from a simple insider-trading rule is its scope of application. The regulation does not only apply to instruments listed on a regulated market like the London Stock Exchange’s main market. It also extends to instruments traded on multichannel trading facilities and organised trading facilities, to related derivatives, and in some cases to conduct that occurs outside the UK if it affects a UK-traded instrument or related derivative. This extraterritorial reach means a transaction executed from overseas can still fall within UK MAR if its effect lands on a UK market.
The regulation also imposes affirmative obligations that have no equivalent in a bare insider-trading prohibition. Issuers must disclose inside information to the market “as soon as possible” unless a narrow delay exemption applies, and they must maintain insider lists identifying everyone with access to sensitive information before it is published. Persons discharging managerial responsibilities, along with their closely associated persons, face notification duties and dealing restrictions around results periods. None of these obligations depend on anyone actually trading; they exist to manage the risk of leakage and to give the FCA a paper trail to investigate if abuse is later suspected.
Why the distinction matters
The practical consequence of this broader framework is that a firm or individual can fall foul of UK MAR without ever possessing inside information and without ever executing an illicit trade. A misleading press statement, a poorly controlled order algorithm that creates artificial price pressure, or a failure to keep an accurate insider list can each trigger regulatory scrutiny, civil penalties, or in serious cases criminal referral, entirely separately from any classic insider-dealing scenario. This is why compliance functions build surveillance systems that monitor order patterns and public communications, not just information barriers around confidential deals.
Seen this way, UK MAR is less a single rule against trading on secrets and more a general framework for market integrity: it polices how information flows, how prices are allowed to form, and how participants are permitted to behave, with insider dealing sitting as just one of several prohibited categories underneath that wider umbrella.