Counterintuitively, rising interest rates make mortgage servicing businesses more valuable. When rates rise, homeowners with existing low-rate mortgages are less likely to refinance or move. This provides the mortgage servicer with a longer, more predictable stream of payments, increasing the value of their servicing rights.

Proposals to allow homeowners to take their low-rate mortgages with them (portability) or transfer them to a buyer (assumability) cannot be retroactively applied due to contract law. Creating new mortgages with these features is possible, but the added benefits to the borrower would likely result in a higher, not lower, interest rate.

A mortgage is not a monolithic loan but a collection of disaggregated risks, such as non-payment and servicing. The U.S. financial system has created separate markets for each risk, which are then sold to different buyers like government-sponsored entities and specialized servicing companies.

Madison Realty's key differentiator is its vertically integrated servicing arm. This allows for rapid, customized solutions to borrower problems (e.g., construction liens, lease modifications) that would get bogged down in a bank's bureaucracy. This operational agility is a core value proposition that institutional borrowers pay a premium for.

Zillow moved from an ad marketplace for mortgages to originating loans itself. This captures margin from a high-cost part of the transaction, but more importantly, it allows Zillow to control and integrate the entire process, solving the consumer pain of juggling multiple vendors and disjointed communication.

Housing unaffordability is being accelerated by the "financialization" of homes. Large institutions and private equity firms are buying up residential properties with the explicit strategy of creating a permanent class of renters. This shifts housing from a personal asset into a financial instrument, profiting from the decline of individual homeownership.

The primary function of mortgage securitization is to move long-term interest rate risk off bank balance sheets. Entities like pension funds, which have long-term liabilities and are less sensitive to short-term rate hikes, are better suited to hold these assets, creating a more stable financial system.

While minor policy tweaks like fee adjustments could lower mortgage costs by 10-15 basis points, more transformative changes are being considered. Allowing homeowners to take their existing mortgage to a new home ("portability") could have a much larger impact on housing market liquidity, but implementing such a change retroactively is deemed extremely difficult from a legal perspective.

A significant cause of today's housing inventory shortage is that homeowners are locked into low-interest mortgages. "Portable mortgages," which are being actively evaluated by the FHFA, would allow homeowners to transfer their existing mortgage to a new property, removing the financial disincentive to move and potentially unlocking market liquidity.