Can I calculate the amortization of an adjustable-rate mortgage portfolio by year by using weighted average margins, maturities, some assumptions on prepayment rate, and index rate?
I have a large residential mortgage portfolio that has fixed and adjustable-rate mortgages. I want to roughly calculate the amortization of the ARM portfolio by year without delving into loan-by-loan calculations. Would that be possible to do by using weighted average margins, maturities, some assumptions on prepayment rate, and index rate?
The correct answer is that you must use a spreadsheet. Enter all the mortgage data and make sure that the calendar months properly correspond in all cases. Then you will have all the data you need until the final mortgage matures. You can find tutorials on the internet which explain this in detail.