Abstract
This paper presents a study on pricing models for CMOs (Collateralized Mortgage Obligations), agreeable to conditions that every tranche's price is represented by a closed-form formula. We redesign seqiiential-pay CMOs so that every tranche's repayment period can be deterministic by controlling initial balance and periodical repayment amount, and adopt two types of pricing model. As an end result, actual instances are mentioned which show that our models provide a closed-form solution for every tranche's price.