...S&P Global Ratings assigned its '##+' rating and stable outlook to Massachusetts Housing Finance Agency's (MassHousing) roughly $70.875 million series 223 single-family housing revenue bonds (SFHRB) (nonalternative-minimum-tax social bonds) and affirmed its '##+' rating, with a stable outlook, and '##+/A-1+' rating, with a stable outlook, on MassHousing's existing debt. MassHousing will partially use series 223 bond proceeds to finance the purchase of about $21.4 million of mortgage-backed securities (MBS) and $49.5 million in whole-mortgage loans, as well as fund $2.3 million of down-payment assistance for borrowers. As part of this transaction, MassHousing will use $39.5 million in other resolution funds for the replacement refunding of previously issued bonds. Series 223 bonds are fixed-rate debt, partially subject to optional and special redemption, as set forth in the official statement....