I appreciate the info. I am an agency mortgage backed security broker. If you can get me 15yr 4's at a 3.03% at the concensus prepayment assumption. I will take 100mm. ( those numbers are for retail mortgages not mortgage backed securities backed by a GSE label) Now at the bottom of that page you will see what mortage backed securites cost.
For example a FNMA 30yr 4% MBS cost 104-18/32 today the yield is 2.43% I have live screens...I buy and sell FNMA and Freddie mac MBS every day.