A significant but continued decline in GSE refinance activity helped contribute to an overall dip in the volume of single-family mortgages securitized by Fannie Mae and Freddie Mac in October, according to a new Inside The GSEs analysis. Fannie and Freddie issued $67.7 billion in single-family mortgage-backed securities in October, a 13.8 percent decline from September but a 2.9 percent rise for the first 10 months of 2013. Deliveries of refinance loans to Fannie and Freddie have declined steadily since January.