Back in 2016, as I was about to leave Fannie Mae [https://www.fanniemae.com], the company was developing a securitization platform with its primary competitor, Freddie Mac. Today the Common Securitization Platform (the firms aren’t known for their creative branding) issues a uniform mortgage-backed security (UMBS). Mortgage-backed securities are an investment instrument backed by the cash flow of pools of residential mortgages. The new security is aimed primarily…