Cross-Currency Heath–Jarrow–Morton Framework in the Multiple-Curve Setting

Abstract. We provide a general Heath–Jarrow–Morton (HJM) framework for forward contracts written on abstract market indices with arbitrary fixing and payment adjustments and featuring collateralization in any currency denomination. In view of this, we first provide a thorough study of cross-currency markets in the presence of collateral and incompleteness. Then we give a general treatment of collateral dislocations by describing the instantaneous cross-currency basis spreads by means of HJM models, for which we derive appropriate drift conditions. The framework obtained allows us to simultaneously cover forward-looking risky IBOR rates, such as EURIBOR, and backward-looking rates based on overnight rates, such as SOFR. Due to the discrepancies in market conventions of different currency areas created by the benchmark transition, this is pivotal for describing portfolios of interest rate products that are denominated in multiple currencies. As an example of a contract simultaneously depending on all the risk factors that we describe within our framework, we treat cross-currency swaps using our proposed abstract indices.