What is insider dealing, and who counts as an insider?

MAR does not punish people simply for being in the know. A person who has inside information commits insider dealing by using it to buy or sell, for their own account or someone else's, directly or indirectly, the financial instruments the information concerns. Using the information to cancel or change an order that was already placed before the person learned it is insider dealing as well, and so is submitting, changing or withdrawing a bid in an emission allowance auction. MAR prohibits both insider dealing and attempts at it.

The ban is tied to the instruments the information relates to, including related derivatives, so an insider may still deal in instruments of unrelated issuers. Timing matters too: a deal completed before the information came into existence cannot be insider dealing, even if the person becomes an insider later. Research or estimates built only from public data are not, in themselves, inside information, so the mere fact of dealing on them is not use of inside information (MAR, recital 28).

A person who has inside information must not recommend, on the basis of that information, that someone else buy or sell, or cancel or amend an order, and must not induce them to do so. The prohibition applies even if the other person never acts. If that person does act, they commit insider dealing themselves when they know, or ought to know, that the recommendation or inducement was based on inside information. Passing the recommendation on to a third party can in turn be unlawful disclosure.

MAR names four groups who hold inside information because of who they are or what they do. They are members of the issuer's board or other administrative, management or supervisory body (or those of an emission allowance market participant); people with a holding in its capital; people with access through their employment, profession or duties, such as an employee preparing board papers or an adviser working on a deal; and people involved in criminal activities. These are often called primary insiders. Anyone else holding inside information, sometimes called a secondary insider, is caught if they know or ought to know that it is inside information. The test is objective: a person who should have realised is treated as an insider, whatever they believed.

Only people who actually received the information hold it; working near the decision is not enough. Where the insider is a company, the rules also reach the individuals who take part in its decision to trade, cancel or amend, as Cyprus Law 102(I)/2016 confirms. The Cypriot criminal law, which applies to serious cases committed intentionally, is narrower for people outside the four groups: they must actually know that the information is inside information.

MAR contains no definition of 'made public'. The exam material uses a test taken from a Cyprus law of 2005: information becomes public once it is known to investors in or outside Cyprus, can be obtained easily and lawfully, sits in records or documents open to public inspection, or has been derived from information already public. That law was repealed in 2016, when Cyprus adopted its laws implementing MAR.

On 16 April 2026 the Court of Justice of the EU ruled (Case C-229/24) that information counts as made public only when it has been disclosed in the way MAR and Implementing Regulation (EU) 2016/1055 require issuers to disclose: to as wide a public as possible, without discrimination, free of charge and simultaneously throughout the Union. Information that anyone could obtain on request, for example under public-records rules, or that has reached only a limited circle, has not been made public. Dissemination through a third party that the issuer has appointed for the purpose, using media the public reasonably relies on, can also qualify. The ruling interprets MAR as it has applied since 3 July 2016. It does not create a new rule.