Securities Settlement System (SSS) is a system which permits the holding and transfer of securities, either free of payment or against payment (delivery versus payment) or against another asset (delivery versus delivery). It comprises all the institutional and technical arrangements required for the settlement of securities trades and the safekeeping of securities. The system can operate on a real-time gross settlement, gross settlement or net settlement basis. A settlement system allows for the calculation (clearing) of the obligations of participants. (Source: OECD)