INTENSITY-BASED MODELS FOR PRICING MORTGAGE-BACKED SECURITIES WITH REPAYMENT RISK UNDER A CIR PROCESS

Under a reduced-form framework, we establish models for pricing mortgage-backed securities with prepayment risk by introducing a stochastic prepayment factor. In the zero-default scenario, the pricing pass-through securities and sequential-pay collateralized mortgage obligation structures are considered. To solve the problems, we introduce a path-dependent variable, from which partial differential equation problems are obtained when the prepayment rate is modeled by a CIR process. Numerical solution to the pricing problem is obtained by developing an explicit characteristics difference scheme.