## The Architecture of a Mortgage
A 30-Year Mortgage Rate is not arbitrarily chosen by a local bank manager. It is explicitly pegged to the 10-Year US Treasury yield, plus a 'MBS Spread.' Historically, banks charge you roughly 1.7% more than the government yield. When that spread explodes to 3.0%, the housing market freezes.
### FAQ
**Q: Why do banks increase the spread even when the Fed pauses rates?**
A: Pre-payment and illiquidity risk. If a bank originates a 7.5% mortgage, and they fear rates will drop to 5.0% next year, they know the borrower will immediately refinance. If the borrower refinances, the investor who bought that Mortgage-Backed Security loses their yield. To compensate for this risk, lenders demand a massive 'Fear Premium' upfront, punishing current homebuyers with abnormally high monthly payments.