A senior CDO tranche that ranks at the very top of a CDO (collateralized debt obligation) issue. Given its utmost, top position of seniority as to other tranches in the structure, this tranche typically sits above the triple-A tranche in the structure and is perceived to be practically risk-free. In the case of default or the CDO’s collateral otherwise underperforms, scheduled payments to super senior tranches take “first” precedence over lower seniority tranches such as senior CDO tranches and mezzanine tranches.

A super senior CDO tranche is assumed to be as a safe underlying cash bond, with a very scant likelihood of default, if any, amongst the entire set of tranches in the CDO issue.