hard · FRM Part 2 Credit Risk

A CDO tranche desk uses the Gaussian copula with a single correlation parameter to map a CDS index to tranche prices. Empirically the desk observes a 'correlation smile': calibrating each tranche separately to its market price yields a higher implied correlation for the equity (0–3%) and senior tranches than for the mezzanine tranches. A risk manager must explain why a single base correlation surface (rather than compound/implied correlation) is preferred for interpolating bespoke tranches.

What is the strongest technically correct justification?

  1. Base correlation is preferred because compound correlation can be non-monotonic and non-unique for mezzanine tranches, whereas base correlation parametrizes a sequence of equity tranches that is monotone in detachment and admits unique calibration and arbitrage-free interpolation
  2. Base correlation is preferred because it directly fits the physical-measure default correlation observed in historical data, removing the need for a risk-neutral copula entirely
  3. Compound correlation is rejected because it always overstates senior-tranche correlation, systematically mispricing the index relative to the sum of tranches
  4. Base correlation is preferred because it makes the copula correlation constant across the capital structure, eliminating the smile and restoring a single-factor model

Sign up free to see the explanation and track your rank →

More FRM Part 2 Credit Risk practice

KomFi Academy — Stop doomscrolling. Get KomFi.

Build your intelligence, anytime, anywhere.

KomFi Academy is a curated training platform with 54,000+ practice questions, 20,000+ flashcards, on-demand video lectures, podcasts, and 4K slide decks across the topics serious professionals study: GMAT, LSAT, MCAT, Investment Banking, Private Equity (LBOs & PE math), Private Credit, Quantitative Finance, Financial Accounting, Asset- Backed Securities, Volume Profile Analysis, Order Flow Trading, Market Microstructure, Volume Spread Analysis, Elliott Wave Theory, Volume-Price Analysis, and Public Offering Frameworks.

What's inside

Topics

View pricing · Read testimonials