Question: What is the impact on GNMA pricing if a pass-through is not fully amortized? What is the present value of a $10 million pool of 15-year mortgages with an 8.5 percent per year monthly mortgage coupon if market rates are 5 percent? The GNMA guarantee fee is 6 basis points and the FI servicing fee is 44 basis points.
a. Assume that the GNMA pass-through is fully amortized.
b. Assume that the GNMA pass-through is only half amortized. There is a lump sum payment at the maturity of the GNMA pass-through that equals 50 percent of the mortgage pool's face value.