When banks originated the loans, they did not keep them on their books, as they did in the old days. Instead, they resold the loans to investment banks or other firms, which pooled those loans with others and converted them into securities. These securities are now owned by people and institutions all over the world. When you pay your mortgage, you make your payment to an intermediary called a loan servicer, which then passes on your payment to the security holders, each of whom receives a miniscule share of it.