A surge in securitization of home purchase-money mortgages during the second quarter was not enough to offset a sizable drop in refinance activity during the first three months of the year, according to a new Inside MBS & ABS analysis and ranking. A total of $372.85 billion of agency single-family MBS was issued during the second quarter, down 3.1 percent from the first three months of 2012. Although securitization of purchase mortgages rose 22.4 percent, partly from seasonal factors as well as firming in the housing market, the volume of refinance loans securitized by Fannie Mae, Freddie Mac and Ginnie Mae declined 10.6 percent.Includes two data charts.