MORTGAGE BACKED SECURITIES: The NHA MBS represents an undivided interest in a pool of insured residential mortgages, As mortgages, these financial instruments are secured by the value of underlying real estate. CMHC provides mortgage loan insurance on all pooled mortgages and unconditional guarantee under the National Housing Act (NHA) of timely payment to NHA MBS investors. These securities, as investments, represent a combination of both real estate mortgages and Canadian government bonds