The decision by the European Court of Human Rights in Soros v. France centered on questions regarding the principle of legality in article 7 ECHR. More precisely, the interpretation of “insider trading” was challenged and whether or not it was possible to appraise whether the French national law had forbade this kind of acts at the respective time. As the principle of legality is a fundamental right in the EU Charter, this decision could significantly influence the principle’s interpretation in the European criminal law area.