Abstract. We present counterparty risk by a jump in the underlying price and a structural change of the price process after the default of the counterparty. The default time is modeled by a default-density approach. Then we study an exponential utility-indifference price of an European option whose underlying asset is exposed to this counterparty risk. Utility-indifference pricing method normally consists in solving two optimization problems. However, by using the minimal entropy martingale measure, we reduce it to solving only one optimal control problem. In addition, to overcome the incompleteness obstacle generated by the possible jump and the change in structure of the price process, we employ the BSDE-decomposition approach in order to decompose the problem into a global-before-default optimal control problem and an after-default one. Each problem works in its own complete framework. We demonstrate the result by numerical simulation of an European option price under the impact of the size of the jump, intensity of the default, absolute risk aversion and change in the underlying volatility. problem and utilize its advantages for an exponential utility function. We then employ the decomposition of the value function before and after default proposed by [4], which separates the problem into after-default and global before-default subproblems, and solves each subproblem by considering a backward stochastic differential equation (BSDE). We solve the utility-indifference price with exponential utility function for a vanilla option whose underlying asset is influenced by counterparty risk in which the underlying asset experiences not only a jump in price, but also changes in its drift and/or volatility.The paper is structured as follows. Section 2 lays out the model and the option pricing problem with a default density hypothesis. In Section 3 we present the minimal entropy martingale measure approach (MEMM) to solve the utility-difference pricing problem as well as the resulting MEMM density of our problem. Once we have this MEMM density, the option price is obtained using the decomposition approach and the BSDE calculation in Section 4. Finally we demonstrate the numerical simulation of a basic European option in Section 5.
Basic definition and hypothesisIn our model, the risky asset subject to a counterparty risk is denoted by a stochastic process S = (S t ) t ¸ 0 . Our objective is to calculate the price of an European derivative (option) mature at a finite time horizon T on this security.We consider a probability space (Ω, Indifference pricing with counterparty riskAbstract. We present counterparty risk by a jump in the underlying price and a structural change of the price process after the default of the counterparty. The default time is modeled by a default-density approach. Then we study an exponential utility-indifference price of an European option whose underlying asset is exposed to this counterparty risk. Utility-indifference pricing method normally consists in solving two optimization problems. Howev...