A brief excerpt:
Here are some graphs on outstanding mortgages by interest rate, the average mortgage interest rate, borrowers’ credit scores and current loan-to-value (LTV) from the FHFA’s National Mortgage Database through Q3 2025 (released this morning).
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This shows the surge in the percent of loans under 3% starting in early 2020 as mortgage rates declined sharply during the pandemic.
Note that a fairly large percentage of mortgage loans were under 4% prior to the pandemic!
The percent of outstanding loans under 4% peaked in Q1 2022 at 65.1% (now at 51.5%), and the percent under 5% peaked at 85.6% (now at 68.6%). These low existing mortgage rates make it difficult for homeowners to sell their homes and buy a new home since their monthly payments would increase sharply.
This was a key reason existing home inventory levels were so low. However, time is eroding this lock-in effect.
There is much more in the article.