gnma-ii means: Register holders of mortgage-backed securities MBS receive an aggregate principal/interest payment from a central pay agent for all certificates. The principal and interest are paid on the 20th of each month. GNMA II MBS can be backed by several-issuer pools, or custom pools with one issuer. However, they may have different interest rates which could vary within one percent. Multi-issuer pools, also known as “jumbos”, are called. The length of jumbo pools is generally greater and they offer mortgages with more geographic diversity than those offered by single-issuer pools. The interest rate on a Jumbo Pool mortgage may differ by one percent. (in Stock Market Dictionary)