Questão jurídica principal
Whether the bank had a contractual or mandate-based duty to demand additional collateral before liquidating the undersecured FX position.
Decisão extraída
No. Absent an express agreement or special circumstances, a bank that is not entrusted with asset management is not obliged to protect the customer’s loss risk by first requesting additional security.
Fundamentação extraída
The collateral margin primarily serves the bank’s own risk limitation. A duty toward the customer arises only if the contract, interpreted under Art. 18 OR, shows a protection obligation. Here no such undertaking was established, and no circumstances required waiting for a margin call; immediate liquidation after missing collateral was therefore not a breach of Art. 398 OR.