I understand the basic workflow of MBS, such as securitization, and.etc. I was wondering the following things:
The relationship between agency product, securities, and pools: Is ONE security exactly backed by ONE underlying pool? How are securities combined together to become a product, such as “FNM30”,”FHL30”.
Approximately how many pools are there from agencies such as Fannie Mae, Freddie Mac, Ginnie Mae, and FHLC?