ABSTRACT
The article presents a theoretic model of tranching in asset securitization. When potential buyers are heterogeneous in the constraint on their portfolios, we find that senior tranche, which is less risky and created by tranching, will introduce more investors and thus reduce risk exposure to investors. Thus, tranching helps improve the sale’s revenue. We also find that the portfolio constraints of investors are always binding at optimum, which is called marginal rating.
Disclosure statement
No potential conflict of interest was reported by the authors.
Notes
1 All the results still hold when type I investors are more risk averse than type II investors, but it becomes more complicated, all proofs will be provided on request.
2 Short sale is implicitly allowed here, and we discuss this issue in next section.
3 Formally, let , where is a positive number. Provided is small enough, we have since by Equation 9 and the function is continuous.