Freddie Mac had one of its best months of the year in terms of new single-family business during October, notching a significant gain in its share of the GSE mortgage-backed securities market.In October, Freddie issued $34.61 billion of single-family MBS, a hefty 23.9 percent increase from the previous month. Meanwhile, Fannie Mae saw a sharp 11.5 percent drop in MBS production from September to October. Freddie’s share of new GSE MBS issuance surged to 45.7 percent last month, its highest level since November of last year, when it spiked to 45.9 percent – and then abruptly fell to just 36.1 percent the following month.