Gnomes The 15-year pass-through securities offered under Freddie Mac's cash program. Investopedia Says: Investors sell their mortgages through Freddie Mac's cash program. The 15-year mortgages sold to Freddie Mac form the pool of mortgages that back the securities referred to as gnomes. Related Terms: Fannie Mae Freddie Mac Ginnie Mae Mortgage Backed Securities - MBS Pass-Through Security |