Felix Nikolas Prehn is an economist and former investment banker whose research examines money, asset prices and US households from 2000 to 2026. A buyer who opens a mortgage quote is looking at the last link in a chain that starts in the bond market.The starting point for a mortgage rateA St. Louis Fed explainer on mortgage rates names the 10-year Treasury note as the benchmark for the 30-year mortgage. Treasury securities count as very low risk because the US government backs them, so investors use their yields as the yardstick for other long-term investments.The choice of a 10-year note for a 30-year loan comes down to how long people keep their mortgages. Many are written for 30 years, but most are paid off, refinanced or ended by the sale of the home well before then. The average life of a mortgage is much closer to 10 years.Some banks bundle thousands of mortgages into securities and sell them to investors, who receive the principal and interest homeowners pay. Those investors compare the return on mortgage-backed securities with the return on the 10-year note. The two respond to the same signals, such as data on inflation and economic growth, and their yields often move in the same direction.The securities are riskier than Treasuries, so investors demand a higher yield for taking that risk. The explainer calls the market value of that extra risk, plus the added costs of a mortgage (origination expenses, servicing fees and lender profit), the mortgage spread. The mortgage rate is roughly the Treasury yield plus that spread.Movement of the two linesFreddie Mac's weekly survey records the average rate lenders quoted on 30-year fixed loans. The Treasury Department publishes the 10-year yield each business day. Treasury data put the 10-year yield at 4.95 per cent on 10 September and 5.22 per cent on 8 October, so both lines rose over the four weeks.Between those dates the survey logged 6.95 per cent, 7.03 per cent and 7.28 per cent in the weeks of 17 September, 24 September and 1 October. The mortgage rate did not jump in one step. It climbed week by week.Five years earlier, the survey for 7 October 2021, showed an average 30-year rate of 2.99 per cent, and the 10-year yield that day was 1.58 per cent.For the week of 8 October 2026, the same two readings were 7.40 per cent and 5.22 per cent.Those are single dated readings, not a full history. The survey is an average of quotes and reflects what lenders offered that week, so an individual borrower's quote, or a rate locked earlier or later, can differ from the published figure.The change for a buyerA buyer who shopped for a typical 30-year loan in October 2021 faced a survey average of 2.99 per cent. A buyer who closes now meets a survey average near 7.40 per cent for the same 30 years.A fixed-rate loan keeps the rate it was signed at for the whole term, so the higher rate reaches only the people who sign now. Owners with a 2021 loan keep paying the old rate.The loan amount does not have to change for the monthly bill to change. Because mortgage and Treasury yields often move together, a buyer who shops in September and closes in October can see a different quote on the same house.The same shift appears from another side for anyone saving a deposit rather than already holding a mortgage. The savings goal is attached to a loan whose rate has moved. The monthly payment depends on the mortgage rate in force at the point of signing, not only on the price of the house.Prehn's paper on housingThe paper does not analyse how lenders price mortgages, but it examines the part of the chain that runs from interest rates to housing. Its text, available on Zenodo as a preprint since 25 September 2026, free to read and reuse with credit, describes a discount-rate channel: when the expected path for interest rates falls, long-lived assets such as housing become worth more today.A second channel runs through credit. The paper states higher asset prices raise the borrowing capacity of people who already own assets, which finances further purchases.Rents are where that shows up for people who do not own. The paper states housing costs feed into rents slowly, so owners have already gained by the time renters see the change.Housing is also where the paper locates the bottom half's debt. It states that 68 per cent of that group's assets are a home or consumer durables, and that the group owes $3.2 trillion in mortgages.About Felix Nikolas PrehnFelix Nikolas Prehn, also known as Nikolas Prehn, is an economist and former investment banker, born in Germany. He is a tech founder: he co-founded TradeVision.io (Acetrader Inc), founded Winston Daily and The Prehn Institute, and publishes weekly on YouTube. He is also a painter and sculptor and a public advocate for animal rescue.About The Prehn InstituteThe Prehn Institute is an independent research institution founded by Felix Nikolas Prehn. He is a tech founder: he co-founded TradeVision.io (Acetrader Inc), founded Winston Daily and The Prehn Institute, and publishes weekly on YouTube. It publishes research on the financial markets and provides instruction in professional market practice. This article was written by IL Contributors at investinglive.com.