AMF Sanctions Seven for Market Manipulation on Euronext Access
France's financial markets regulator has confirmed that seven individuals and entities face financial penalties following a coordinated scheme to artificially inflate the apparent liquidity of shares listed on Euronext Access. The Paris Court of Appeal upheld the sanctions against one respondent in June 2026, closing off a key avenue of challenge and cementing the regulatory outcome. For compliance teams, auditors, and CFOs with exposure to French or EU equity markets, the case is a concrete illustration of how coordinated trading behaviour is identified, prosecuted, and ultimately confirmed at appellate level.
What the AMF Enforcement Commission Decided
In its decision of 24 January 2024 (SAN-2024-02), the AMF Enforcement Commission imposed financial penalties on four parties for market price manipulation and on three company directors for declaration obligation breaches. The penalties for manipulation ranged from €400,000 to €2,000,000. Those relating to disclosure failures ranged from €25,000 to €100,000.
The entities and individuals sanctioned
The manipulation sanctions covered Grantchester Equity Ltd, Miron Leshem, Dirck Van Wylick, and Aude Planche. The disclosure penalties applied to the directors of the three listed companies: Serge Goldner, Christian Person, and Léon Lucide. The three companies whose shares were at the centre of the scheme were Gour Medical, Umalis Group, and CIOA, all traded on Euronext Access.
How the manipulation scheme worked
The Commission found that a single coordinated pattern was applied across all three securities. Multiple actors worked together to create the impression of abundant liquidity where none genuinely existed. This behaviour was characterised as market price manipulation on four grounds: fixing prices at an abnormal or artificial level; giving false or misleading signals about supply, demand, or price; using fictitious devices or other forms of deception; and building a dominant position capable of controlling buying and selling prices.
Grantchester Equity Ltd and its president, Leshem, were identified as the architects of the strategy. They designed it, controlled its execution, and extracted substantial economic benefit from it. Van Wylick and Planche were found to have collaborated materially in carrying out the scheme, which was sufficient for the manipulation breach to be established against them individually. The company directors — Goldner, Person, and Lucide — were separately found to have failed to declare their transactions as required.
The Appellate Outcomes
Two respondents challenged the decision before the Paris Court of Appeal. Their cases reached different conclusions, and the timeline matters for compliance teams tracking the finality of French enforcement actions.
Aude Planche: appeal rejected
On 11 June 2026, the Paris Court of Appeal rejected Planche's challenge to the January 2024 decision. The court also declined to refer a question of EU law to the Court of Justice of the European Union, which had been one of the grounds raised. The sanction against her stands in full.
Earlier, in July 2024, a judge delegated by the First President of the Paris Court of Appeal had ordered a partial stay of execution pending the appeal. That stay, excluding publication of the decision, has now been superseded by the court's rejection of the appeal on the merits.
Christian Person: withdrawal
By order of 19 March 2026, the Paris Court of Appeal recorded Person's withdrawal from his own appeal. A July 2024 application for a stay of execution had already been refused for him, so the original sanction remained enforceable throughout. His withdrawal means no substantive ruling on the merits was issued in his case.
Compliance Implications for Firms and Advisers
Several aspects of the case carry direct relevance for accounting firms, auditors, and compliance officers advising clients with exposure to French or broader EU regulated markets.
Coordination risk and aggregated liability
The Commission did not require proof that each party personally executed every trade. Collaboration in a scheme is enough to attract liability. Firms advising clients who participate in structured trading arrangements, whether as market makers, strategic shareholders, or intermediaries, should be alert to how regulators characterise coordinated activity. The facts here show that even parties at the periphery of an arrangement can be held accountable if their involvement is material.
Declaration obligations carry real penalties
The three director respondents were not accused of manipulation itself, only of failing to file required transaction disclosures. Yet each faced a financial sanction. Compliance programmes that treat declaration obligations as a low-priority administrative matter are underestimating the exposure. European enforcement actions increasingly hold firms and their advisers to account for procedural breaches, not just substantive misconduct.
Appellate confirmation extends the enforcement lifecycle
The June 2026 ruling means this case is now over two years old from the original decision, yet it is still generating enforcement news. Compliance teams should model enforcement timelines accordingly. A sanction is not final when it is issued; it may be challenged, stayed, and then upheld, with reputational and operational consequences persisting throughout. Cross-border enforcement cases offer parallel lessons about how regulatory findings evolve post-decision.
EU law arguments did not succeed
Planche's legal team sought to raise a question for the Court of Justice of the EU. The Paris court declined. This matters because it confirms that the AMF's domestic framework for market manipulation, applied here to Euronext Access securities, is robust enough to withstand challenges framed in EU law terms. Advisers should not assume that EU-level arguments will provide a reliable route out of AMF enforcement.
About the AMF Enforcement Commission
The AMF Enforcement Commission operates with full decision-making independence. It can sanction any person or entity whose conduct violates laws and regulations within the AMF's jurisdiction. It also approves settlement agreements negotiated between the AMF Secretary General and respondents, and it uses its published decisions to clarify the regulatory framework for market participants.
What securities were at the centre of the manipulation?
The shares of Gour Medical, Umalis Group, and CIOA, all listed on Euronext Access, were the subject of the coordinated manipulation scheme identified by the AMF Enforcement Commission.
What penalty levels did the AMF impose?
The four parties found liable for market manipulation received financial penalties between €400,000 and €2,000,000. The three directors sanctioned for declaration breaches received penalties between €25,000 and €100,000.
What did the Paris Court of Appeal decide?
On 11 June 2026, the court rejected Aude Planche's challenge and declined to refer an EU law question to the Court of Justice. Christian Person had separately withdrawn his appeal, which was recorded by the court on 19 March 2026.
Can a director face sanctions even without personally trading?
Yes. The three company directors in this case were sanctioned not for manipulation but for failing to fulfil their transaction reporting obligations. The AMF treats declaration breaches as a distinct and separately punishable category of misconduct.
Does an EU law argument provide protection against AMF sanctions?
Based on this case, not automatically. The Paris Court of Appeal declined to refer Planche's EU law question to the Court of Justice of the European Union, meaning the AMF's domestic legal framework was applied and upheld without requiring EU-level clarification.
FAQ
The shares of Gour Medical, Umalis Group, and CIOA, all listed on Euronext Access, were the subject of the coordinated manipulation scheme identified by the AMF Enforcement Commission.
The four parties found liable for market manipulation received financial penalties between €400,000 and €2,000,000. The three directors sanctioned for declaration breaches received penalties between €25,000 and €100,000.
On 11 June 2026, the court rejected Aude Planche's challenge and declined to refer an EU law question to the Court of Justice. Christian Person had separately withdrawn his appeal, recorded by the court on 19 March 2026.
Yes. The three company directors in this case were sanctioned not for manipulation but for failing to fulfil their transaction reporting obligations. The AMF treats declaration breaches as a distinct and separately punishable category of misconduct.
Based on this case, not automatically. The Paris Court of Appeal declined to refer the EU law question to the Court of Justice of the European Union, meaning the AMF's domestic legal framework was applied and upheld without requiring EU-level clarification.