The Market Abuse Regulation (MAR) is the rulebook that keeps financial markets honest. It prohibits insider dealing, the unlawful disclosure of inside information, and market manipulation, and it sets out what issuers and firms must do to prove they are playing fair.
For any business with securities on a trading venue, MAR is not optional reading. It shapes when you disclose price-sensitive news, who you record as an insider, and what your directors can and cannot do with company shares.
This guide explains what the regulation covers, who is in scope, and how the UK version works after Brexit. It also shows where the Legal Entity Identifier fits, because the reports that let regulators police market abuse identify the firms and issuers behind them. At LEI24 we help companies obtain and manage the LEIs that exactly this kind of entity needs.
What Is the Market Abuse Regulation?
The Market Abuse Regulation is Regulation (EU) 596/2014, which came into force on 3 July 2016 and replaced the older Market Abuse Directive. Its purpose is simple to state and hard to police: protect market integrity and investor confidence by making sure no one profits from information or tactics that other investors do not have.
It does that by banning three behaviours outright and by placing ongoing obligations on the people and companies closest to price-sensitive information. Those two halves, the prohibitions and the duties, are what most of the rest of this guide is about. In practice, MAR is one of the most consequential parts of the UK’s wider regulatory reporting landscape, because breaching it carries both financial and criminal risk.
UK MAR vs EU MAR After Brexit
MAR started life as EU law that applied directly across member states. After Brexit, it was onshored into UK law on 31 December 2020, becoming what is now known as UK MAR. The Financial Conduct Authority (FCA) is the UK regulator responsible for it.
Since 1 January 2021, there have been two parallel regimes: UK MAR and EU MAR. They are closely aligned, but they are separate.
The practical catch is dual listing. A company with instruments admitted to trading in both the UK and the EU has to comply with both regimes and make its notifications to two authorities, the FCA and the relevant EU regulator. For firms that operate on only one side, a single regime applies.
Who Does MAR Apply To?
MAR is triggered by where an instrument trades, not by where a company is based. It applies to financial instruments that are admitted to trading, or for which admission has been requested, on a UK regulated market, and to instruments traded or admitted on a UK multilateral trading facility (MTF) or organised trading facility (OTF). It also reaches instruments whose price depends on or affects an in-scope instrument, such as certain derivatives.
That pulls a broad group into scope:
- Issuers with securities on a UK trading venue.
- Firms that arrange or execute transactions in those instruments.
- Individuals with access to inside information, including company insiders and persons discharging managerial responsibilities.
If your instruments trade on a venue, you are almost certainly in scope, whatever your size.
The Three Types of Market Abuse
MAR prohibits three distinct behaviours. Understanding the line each one draws is the core of staying on the right side of the regulation.
Insider Dealing
Insider dealing is using inside information to trade, or to try to trade, in the relevant financial instruments. It also covers recommending or inducing someone else to trade on that basis. The key point is that acting on non-public, price-sensitive information gives an unfair edge, and that is what the rule removes.
Unlawful Disclosure of Inside Information
This is passing inside information to another person outside the normal course of your job, profession or duties. You do not have to trade to break this rule. Simply tipping someone off, whether or not they act on it, is enough.
Market Manipulation
Market manipulation covers actions that give false or misleading signals about the supply, demand or price of an instrument, or that secure its price at an artificial level. It captures a wide range of tactics, including spreading misleading information and certain forms of benchmark and commodity manipulation, and it reaches attempted manipulation as well.
What Counts as Inside Information?
Almost everything in MAR turns on this definition. Inside information is information of a precise nature, that has not been made public, relating to one or more issuers or financial instruments, which, if it were made public, would be likely to have a significant effect on the price of those instruments.
Break that into a four-part test and it becomes workable. The information must be precise, it must be non-public, it must relate to an issuer or an instrument, and it must be price-sensitive. Only when all four are present is the information genuinely inside information, and only then do the disclosure and dealing rules bite.
Key Obligations Under MAR
Beyond the prohibitions, MAR places active duties on issuers and the people around them. These are the obligations the FCA checks in practice.
Disclosing Inside Information
Issuers must disclose inside information that directly concerns them to the market as soon as possible, so that all investors learn it at the same time. Disclosure can be delayed in limited circumstances, for example to protect a live negotiation, provided the delay does not mislead the public and the information is kept confidential in the meantime.
Maintaining Insider Lists
Issuers, and anyone acting on their behalf, must keep insider lists recording everyone who has access to inside information. A separate list is kept for each distinct piece of inside information, and it must be handed to the FCA on request. Well-kept insider lists are one of the first things the regulator looks at when it investigates.
PDMR Transaction Notifications
Persons discharging managerial responsibilities (PDMRs), typically directors and senior executives, and the people closely associated with them, must notify both the issuer and the FCA of their own dealings in the company’s instruments once those dealings pass the threshold set in the rules within a calendar year. The issuer then has a short, defined window to announce the transaction to the market.
Market Soundings
A market sounding is the controlled disclosure of information, sometimes including inside information, to gauge investor interest ahead of a transaction. MAR sets out a process for doing this cleanly, including making the recipient aware of their obligations, so that legitimate deal preparation does not tip into unlawful disclosure.
Suspicious Transaction and Order Reports (STORs)
Firms and venues that arrange or execute transactions must watch for signs of insider dealing or manipulation and file Suspicious Transaction and Order Reports with the FCA without undue delay. STORs are a frontline surveillance tool, and the quality of a firm’s STOR process is something the regulator scrutinises closely.
Penalties for Breaching MAR
The consequences of getting MAR wrong are serious. The FCA can impose unlimited fines and public censure on firms and individuals, and it regularly does.
Market abuse can also be criminal. Insider dealing is an offence under the Criminal Justice Act 1993, and the maximum prison sentence for it was raised to ten years under the Financial Services Act 2021. On top of the legal exposure sits reputational damage, which for a listed issuer can be just as costly as any fine.
How an LEI Supports MAR Reporting and Market Integrity
The instruments MAR governs are, almost by definition, instruments admitted to trading on a venue.
A Legal Entity Identifier may be needed under the wider trading and reporting framework around trading venues, especially where UK MiFIR transaction-reporting rules apply. In particular, firms subject to UK MiFIR transaction-reporting obligations cannot execute a trade on behalf of an LEI-eligible client that does not have an LEI.
That identifier does real work in policing market abuse. The transaction reports and reports firms submit to the FCA identify the entities involved by their LEI, which is how a regulator connects an order, a firm and an issuer when it looks for a pattern of abuse. A clean, accurate LEI is part of the plumbing that makes surveillance possible.
It also helps in the other direction. Before dealing with a counterparty, a quick LEI search confirms exactly which legal entity you are facing.
If your own instruments are heading to a trading venue, checking who needs an LEI number early keeps that requirement from becoming a last-minute blocker.
How to Stay Compliant With MAR
Compliance with MAR is less about a single policy and more about consistent habits across the business. A few practices carry most of the weight.
Build clear internal procedures covering inside information, insider lists and PDMR dealings, and train the people who touch price-sensitive information so they recognise it. Invest in surveillance that can actually detect suspicious orders and support timely STORs, and treat insider-list hygiene as an ongoing task rather than a scramble when the FCA asks. Folding all of this into your broader financial compliance routine keeps it from drifting.
Keep your identifiers in order too. An out-of-date LEI can create friction across the reporting that supports market integrity, so a timely LEI renewal belongs on the same compliance calendar as everything else.
Frequently Asked Questions
What does the Market Abuse Regulation prohibit?
MAR prohibits three behaviours: insider dealing, the unlawful disclosure of inside information, and market manipulation. It covers attempts as well as completed acts.
Who does the Market Abuse Regulation apply to?
It applies to issuers with instruments on UK regulated markets, MTFs or OTFs, to firms that arrange or execute transactions in those instruments, and to individuals with access to inside information such as insiders and PDMRs. Scope follows where the instrument trades, not where the company is based.
What is the difference between UK MAR and EU MAR?
They are two separate but closely aligned regimes. EU MAR applies to instruments on EU venues, and UK MAR applies to instruments on UK venues, with the FCA as the UK regulator. A dual-listed issuer must comply with both and notify two authorities.
What is a PDMR under MAR?
A person discharging managerial responsibilities is a director or senior executive with regular access to inside information and authority over the company’s decisions. PDMRs and the people closely associated with them must notify their dealings in the company’s instruments to the issuer and the FCA.
What is an insider list?
An insider list is a record of everyone who has access to a specific piece of inside information. Issuers and those acting on their behalf must maintain these lists and provide them to the FCA on request.
Do issuers need an LEI under MAR?
MAR does not itself create a standalone LEI requirement. However, LEIs can still be relevant under the wider UK trading and reporting framework, especially where UK MiFIR transaction-reporting obligations apply. In particular, firms subject to those obligations cannot execute a trade on behalf of an LEI-eligible client that does not have an LEI.
