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Credit Risk in Derivative Pricing. Frédéric Abergel Chair of Quantitative Finance École Centrale de Paris. Implicit Credit Risk. Every financial product is subject to credit risk Example : a contract with A on the stock S of the company B Payoff Counterparty risk Default risk.
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Credit Risk in Derivative Pricing Frédéric Abergel Chair of Quantitative Finance École Centrale de Paris
Implicit Credit Risk • Every financial product is subject to credit risk • Example : a contract with A on the stock S of the company B • Payoff • Counterparty risk • Default risk
Implicit Credit Risk • Several issues : • Is credit risk priced in the derivatives ? • Can it be hedged out using market instruments? • Should it be made more explicit ?
Implicit Credit Risk • A basic example : consistent pricing of CDS, Bonds and Vanilla options • An intensity-based credit model • are preferrably stochastic. • Convertible J = 0, exchangeable J = 1 • Model calibration • On options, CDS, convertible bonds • Joint calibration not always possible • Credit risk is generally not priced in the long vanillas
Hedging out the credit risk • A simple joint modelling for the stock of company A and the default of company B • spread/stock correlation • (J-1): size of the jump of the stock of A if B defaults
Hedging out the credit risk • Continuous trading in stock and CDS’s allows a theoretical risk neutralization • Identification of the market risk premiums • risk-neutral hazard rate • risk-neutral drifts • Practical concerns • Liquidity of the CDS market • Shape of the curve : roll or hold ? • Estimate of J when J is not 0 nor 1 ? • Price aggressiveness ?
Making the risk more explicit • Trivial example : Credit Contingent Stock • the contract is to deliver one stock of company A subject to company B not defaulting • Payoff • Variables can be separated
Making the risk more explicit • Particular solution • where Q is a “risky bond” with correlation and jump corrections
Making the risk more explicit • In the “fully decorrelated case” case, one recovers a simple pricing formula: stock * survival probability • In general, the hedge is not identically “long one stock”: • as maturity approaches and no credit event occurs, it will tend to 1 • the rebalancing in stock is financed by being structurally seller of CDS.
Making the risk more explicit • Cancellable options • Payoff conditional to a credit event not occuring • Equity financing • Cancellable swaps • Contingent CDS • Pay : fixed quarterly coupon until default • Receive : Option value at default time • Many generalizations…