The Graubünden Cantonal Bank (GCB) and its subsidiary BZ Bank are facing a lawsuit demanding millions in compensation for alleged breaches of duty in connection with an investment product. + Get the most important news from Switzerland in your inbox A lawsuit has been filed against both banks plus current and former executive bodies of BZ Bank. The plaintiff is demanding a sum in the mid three-digit million range, according to a GCB statement. The banks deny the allegations. According to the statement, the lawsuit is in connection with a client relationship and an investment product managed by BZ Bank. The unnamed plaintiff is accusing the financial institutions of breaches of duty. GCB and BZ Bank consider the allegations to be unfounded and deny the claims, and say they will defend themselves. According to the press release, the claim was submitted to the Höfe mediation office in the form of a request for arbitration. GCB bought a majority stake in BZ Bank from Swiss investor …