Fine-tuning the equivalent strike framework for bespoke cdo tranches pricing

This paper presents a fine-tuning of some mapping functions used in the Equivalent Strike framework. This new approach provides an equivalent strike that is independent from the index base correlation. This feature is valuable when pricing very junior and senior tranches or when computing index tranches (or index base correlation) sensitivities. Our numerical tests on realistic cases showed that the equivalent correlation provided by this new is pretty close to what is computed with common mapping functions.