CDO

A CDO is a collateralized debt obligation or collateralised debt obligation known collectively as CDOs.
CDOs are a type of asset-backed security or structured credit product that offers exposure to the credit of a portfolio of fixed income assets, such as corporate or government debt, loans, asset-backed securities (ABS), including mortgage-backed securities (MBS) such as CMBS and MBS, known as CDOs of ABS or ABS CDOs, or other CDOs, known as CDO-squared or CDOs of CDOs. CDOs can be cashflow CDOs (referencing real assets) or synthetic CDOs (referencing credit derivatives, such as CDS) or hybrid CDOs (a mix of cashflow and synthetic). Typical CDOs divide the credit risk among different tranches: senior tranches (rated AAA), mezzanine tranches (AA to B) and equity tranches (unrated). Losses are applied in reverse order of seniority and so junior tranches offer higher coupons to compensate for the added risk. However, synthetic CDOs can be structured to offer single-tranche CDOs as well.