While falling mortgage rates will improve affordability, the "lock-in effect" for existing homeowners with ultra-low rates will persist. This will suppress the typical sales volume rebound, leading to an anemic 3% growth in purchase volumes, a historically tepid response to improved affordability conditions.

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.

Widespread homeowner reluctance to give up low mortgage rates is the main cause of critically low housing inventory. This lack of supply, not strong demand, is the primary reason home prices remain at record highs, preventing a market correction despite low sales volume.

The historically low number of home sales isn't just about buyer affordability. A major factor is seller reluctance; existing homeowners are "locked in" by their low-rate mortgages and find it financially unattractive to sell and buy a new property at current higher rates.

While lower mortgage rates typically boost buyer demand, they also reduce the 'lock-in effect' for existing homeowners. This brings more supply to the market, which will likely offset the increased demand and keep home price growth minimal and 'range-bound'.

The US housing market is frozen not by insolvency but because homeowners are locked into low mortgage rates. With transactions at crisis-era lows but driven by non-discretionary events like death and divorce, pent-up demand creates a "coiled spring" scenario for when rates ease.

A significant housing market recovery requires a substantial and sustained improvement in affordability. Analysts estimate a 100-basis-point drop in mortgage rates (e.g., to 5.5%) is needed to trigger a meaningful pickup in sales. However, this growth is not immediate; sustainable increases in sales volumes typically materialize a full year after the affordability improvement occurs.

Mortgage payments aren't split evenly. For the first 15-20 years of a 30-year loan, the majority of your payment is pure interest enriching the bank, not building your equity. You build very little ownership in the early stages, and refinancing resets this clock.