The principle of subsidiarity is a fundamental principle of the European Union which stipulates that decisions should be made at the level closest to citizens. In the context of ESMA intervention powers, this principle means that ESMA only intervenes if no national competent authority has acted or if the actions taken do not adequately address the threat.

Article 42 of the MiFIR Regulation stipulates that national authorities must notify their proposed measures with at least one month's notice before the intended effective date. An emergency procedure allows twenty-four hours' notice for provisional measures limited to three months.

Under Article 40 of the MiFIR Regulation, ESMA measures are temporary and their maximum duration has been set at six months since the 2022 revisions. This duration was previously three months. The measures must be reviewed at appropriate intervals, at least every six months, and may be renewed if necessary.

ESMA restrictions on CFDs, introduced in August 2018, set variable leverage limits depending on the asset type. For crypto-assets, the limit is particularly low at 2:1 to reflect their high volatility. Other limits include 30:1 for major currency pairs.

Under Article L. 621-30 of the Code monétaire et financier (CMF), the Conseil d'État has jurisdiction over individual decisions concerning investment service providers taken by the AMF. The Paris Court of Appeal has jurisdiction over other individual decisions and sanctions. This dual jurisdictional system must be well understood to identify the appropriate avenue of appeal.

ESMA measures are defined as temporary with a maximum duration of six months, renewable. By contrast, national authorities, such as the AMF in France, may take permanent measures. This difference is a key aspect of the division of competences between ESMA and national authorities.

ESMA intervention powers are temporary and require compliance with the subsidiarity principle. National authority powers may be permanent and must follow specific procedures such as one-month notice or an emergency procedure for provisional measures.

For ESMA to intervene, three conditions must be met: (1) a significant concern for investor protection, the orderly functioning of markets or the stability of the financial system; (2) the applicable EU regulatory requirements must be insufficient to address the threat; (3) no national competent authority has acted or the actions taken do not adequately address the threat.