Mortgage-backed securities channel funds to the housing market without requiring that banks or thrift institutions make loans from their own portfolios. 这是投资学第九版后面习题答案中 ，资产证券化为市场参与者避开金融中介机构提供了一种渠道举得例子，感觉有点无法理解。哪位大神帮翻一下~