A company listed on a German stock exchange must publish inside information that directly concerns it unverzüglich, without delay. The rule is Article 17 of the EU Market Abuse Regulation. Germans call such a notice an Ad-hoc-Mitteilung. The financial supervisor BaFin explains the purpose. Other investors should not be at a disadvantage to company insiders. On 18 September 2015, US authorities published a notice of violation against Volkswagen over manipulated diesel engines. VW sent its first ad hoc notice on 22 September. At times its preferred shares lost almost half their value. By September 2018, investors had filed 1,668 claims for almost nine billion euros. One of the plaintiffs’ lawyers argued that VW should have informed the market by June 2008 at the latest. VW disputed this. The former chief executive Martin Winterkorn was later put on trial, among other charges, because the market had not been informed in the decisive days of September 2015.