What does MAR prohibit, and when is holding or sharing inside information lawful?

Article 14 of MAR sets three prohibitions. No one may engage in insider dealing or attempt it; no one may recommend that another person engage in insider dealing or induce them to do so; and no one may unlawfully disclose inside information. Market manipulation has its own ban in Article 15. Knowing inside information is therefore not in itself a breach: what is forbidden is using it, getting others to use it, or passing it on outside the normal exercise of an employment, profession or duties. A person who is told inside information and does nothing with it commits no offence; if they trade, recommend or pass it on, they may.

For a company, use of inside information is not presumed simply because someone inside it knew. The company is protected if it had put in place, operated and kept up adequate, effective internal arrangements and procedures, such as information barriers, that made sure neither the person who took the decision to deal nor anyone who could influence that decision had the information, and it did not encourage, advise, induce or otherwise influence that person.

Several activities are also protected. A market maker or authorised counterparty may deal legitimately in the normal course of that role. A broker may legitimately carry out a client's order. A person may carry out a transaction to meet an obligation that has fallen due, in good faith and not to get round the ban, if the obligation arose before they had the information: from an order placed, an agreement concluded, or a legal or regulatory duty. Using inside information solely to go ahead with a public takeover or merger is allowed if the information has been published or has stopped being inside by the time shareholders approve or accept. This never covers stake-building. Using one's own knowledge of one's own decision to buy or sell is not, in itself, use of inside information. In all of these cases, the regulator can still find a breach if it shows there was an illegitimate reason for the deal.

Disclosure is unlawful whenever a person who has inside information passes it to anyone else, unless it happens in the normal exercise of an employment, a profession or duties. Sharing information with the lawyers or auditors working on a transaction, or with colleagues who need it for their work, falls within normal duties. The exception is read strictly: the disclosure must be necessary for that work and proportionate. On 18 June 2026 the Court of Justice of the EU ruled (Case C-376/24) that a politician who reveals inside information in the media to open a public debate can meet this test, with freedom of expression taken into account. Mentioning it to a family member or friend does not, and is unlawful disclosure by the person who speaks, even if the listener does nothing with it. A confidentiality agreement does not turn a disclosure made outside normal duties into a lawful one. Disclosures in a market sounding that follows MAR's procedure are treated as made in the normal exercise of duties.

Onward disclosure is also caught: someone who passes on a recommendation or inducement commits unlawful disclosure if they know or ought to know that it was based on inside information. The Cypriot criminal law, Law 136(I)/2016, repeats the exception for the normal exercise of duties, expressly excludes compliant market soundings from the disclosure offence, and applies MAR's legitimate-behaviour cases to the criminal insider-dealing offence.