Article 50 of the Charter of Fundamental Rights of the European Union must be interpreted as precluding national legislation which permits the possibility of bringing administrative proceedings against a person in respect of unlawful conduct consisting in market manipulation for which the same person has already been finally convicted, in so far as that conviction is, given the harm caused to the company by the offence committed, such as to punish that offence in an effective, proportionate and dissuasive manner. The ne bis in idem principle guaranteed by Article 50 of the Charter of Fundamental Rights of the European Union confers on individuals a right which is directly applicable in the context of a dispute such as that at issue in the main proceedings.