As Fannie Mae’s and Freddie Mac’s portfolios wind down, the two GSEs should maintain sufficient balance sheet space to allow for the aggregation of loans from smaller lenders who are not yet ready to securitize, according to the Mortgage Bankers Association. The MBA’s “concept paper” released this week also calls for the Federal Housing Finance Agency common securitization platform initiative to include plans for the acceptance of small lot deliveries into multi-lender pools.