This is a case study of the German securities regulator's (BAFin) decision on the Schaeffler case of 21 August 2008, which concluded that the Schaeffler Group's strategy for building up a controlling stake in Continental AG did not violate German disclosure rules. Moreover, it assesses whether the Schaeffler strategy would have been disclosed if the amendments to the German disclosure rules made by the Risk Limitations Act of 21 August 2008 had been in force at the time Schaeffler built up its swap position in Conti. In contrast to BAFin's decision, I hold that Schaeffler's swap long positions prompted disclosure requirements under the ‘holding on behalf’ provision of Article 10(g) of the European Transparency Directive 2004/109 as implemented in German securities and takeover law. While BAFin's decision was subject to the specifics of the case at hand, inadequate enforcement rules help explain why Schaeffler took the risk of regulatory action in the first place. Rather than relying on ex-post enforcement, I argue in favour of developing a self-regulatory, ex-ante enforcement scheme using the model provided by antitrust leniency programmes.