The invention relates to a computer-implemented method, system and non-transitory medium for managing debt instrument. Insuring for a default of a debt is managed by establishing an insuring debt related to an insured debt of a debtor based on an insured debt amount of the insured debt. The debts can be bonds issued by a municipality. A first loss class and a second loss class can be allocated in an insuring trust. A first class holder can be entitled to a payment from the insuring debt based on a debt owed to the first class holder from an established insuring fund of the insuring trust. The insuring fund is used to insure for a default of the insured debt. If the insured debt is not in default, the payment is diverted to the first class holder. Otherwise, the payment is intercepted, and an insuring payment from the insuring fund is paid to a holder of the insured debt to cure the default.