Financial/Actuarial Mathematics Seminar

Thursdays 3:10-4:00, 3088 East Hall



Wiener-Hopf factorization as a general method for valuation of real and American options

Sergey Levendorskiy

Department of Economics, University of Texas at Austin

January 24, 2008



Abstract

A new general approach to optimal stopping problems in L\'evy models, regime switching L\'evy models and L\'evy models with stochastic volatility and stochastic interest rate is developed. For perpetual options, explicit solutions are found, for options with finite time horizon, time discretization is used, and explicit solutions are derived for resulting sequences of perpetual options.

The main building block is the option to abandon a monotone payoff stream. The optimal exercise boundary is found using the operator form of the Wiener-Hopf method which is standard in analysis and interpretation of the factors as {\em expected present value operators} (EPV-operators) under supremum and infimum processes. Other types of options are reduced to the option to abandon a monotone stream. For regime-switching models, an additional ingredient is an efficient iteration procedure. L\'evy models with stochastic volatility and/or stochastic interest rate are reduced to regime switching models using the discretization of the state space of additional factors. The efficiency of the method for 2 factor models with jumps and for 3-factor Heston model with stochastic interest rate is demonstrated.
This is joint work with S. Boyarchenko.


Back to the schedule