The cum-cum deals, in which the Sparkasse and the Volksbanken were also involved, defrauded the state of an estimated 25 billion euros. Securities traders from London and bankers from Frankfurt, Hamburg and Stuttgart were involved. Prof. Spengel explains how the share transactions resulted in unlawful tax refunds and how this may have caused greater financial damage than the cum-ex transactions.

You can find the Zeit article here.

You can find the Badische neueste Nachrichten article here.