Fannie Mae and Freddie Mac saw a largely seasonal decline in single-family business in October, according to a new Inside The GSEs analysis of mortgage-backed securities data. The two GSEs guaranteed $99.33 billion of single-family MBS during October, an 8.3 percent decline from the previous month. Most of the slippage was in purchase-money mortgages, which fell 14.5 percent from September, following typical seasonal patterns. The refi market held up a lot better. October volume was down 1.6 percent from September, while still ranking as the second-highest monthly total so far this year. That pushed the refi business to 60.2 percent of GSE volume, excluding modified loans.