Single-Tranche CDOs

Single-Tranche CDOs, also called bespoke tranches, are customized synthetic CDO tranches created for specific investors without issuing the remaining capital structure, providing tailored credit risk exposure. Unlike traditional CDOs requiring placement of all tranches, single-tranche CDOs exist through dealer hedging of retained risks. For example, an investor seeking 5-year protection on the 3-7% tranche of 100 investment-grade credits receives customized exposure while the dealer dynamically hedges using single-name CDS. Benefits include complete customization of reference portfolio, attachment points, and maturity; no requirement to place other tranches; and faster execution than full CDOs. Pricing requires sophisticated correlation modeling and includes dealer profit for warehousing risks. Risks include model dependence, dealer counterparty exposure, and limited price transparency. The market evolved from pre-crisis excess to more conservative structures referencing liquid indices. Recent innovations include ESG-screened reference portfolios and tranches linked to climate transition risks. Single-tranche CDOs demonstrate evolution toward mass customization in structured credit, though complexity requires sophisticated investors.