CommerzVentures has led a €25 million Series B financing round in Estonian core banking provider Tuum. : CommerzVentures has led a €25 million Series B financing round in Estonian core banking provider Tuum. CommerzVentures, the fintech venture arm of German bank Commerzbank, was joined in the round by Speedinvest and existing investors. Tumm last raised €1 million from client bank and BaaS component supplier LHV in April 2022.