Fixed-Rate Mortgage

A fixed-rate mortgage is a mortgage loan in which the interest rate is set at origination and remains unchanged for the entire life of the loan. The borrower's monthly payment of principal and interest stays the same from the first payment to the last, regardless of what happens to market interest rates during the term. This predictability is the defining advantage of a fixed-rate mortgage for borrowers -- and a key valuation feature for note investors.

How a Fixed-Rate Mortgage Works

The mechanics of a fixed-rate mortgage are straightforward. At origination, the lender and borrower agree on a principal amount, an interest rate, and a term (most commonly 15 or 30 years). The loan is then fully amortized -- meaning each monthly payment includes both interest and principal, calculated so that the balance reaches zero at the end of the term.

In the early years, the majority of each payment goes toward interest. As the loan matures, the interest portion shrinks and the principal portion grows. This is standard amortization math, and it applies identically to every fixed-rate mortgage regardless of the rate or term.

Fixed-Rate vs. Adjustable-Rate Mortgages

The primary alternative to a fixed-rate mortgage is an adjustable-rate mortgage (ARM), which offers a lower initial rate that adjusts periodically based on a market index. The tradeoff:

The 2008 financial crisis was driven in large part by borrowers who were originated into adjustable-rate products they could not afford once rates reset. That history is one reason fixed-rate mortgages dominate origination volume today and constitute the majority of loans in secondary market note pools.

Why Fixed-Rate Mortgages Matter to Note Investors

Pricing and Yield

Fixed-rate mortgages are the easiest loan type to value because the cash flows are fully deterministic. If a performing loan has a 6% fixed rate, a $100,000 UPB, and 240 months remaining, you can calculate the exact stream of payments the borrower owes. Discounting those payments by your target yield produces a maximum purchase price. There is no rate-adjustment uncertainty to model.

Performing Note Cash Flows

For performing note investors, fixed-rate mortgages purchased at a discount to UPB produce a yield higher than the note's stated rate. For example, buying a 5% fixed-rate note at 85 cents on the dollar increases your effective yield because you paid less than face value for the same stream of payments. This spread between the note rate and your effective yield is the fundamental source of return in performing note investing.

Non-Performing Note Considerations

When a fixed-rate mortgage becomes a non-performing loan, the original rate is less important than the resolution strategy. Note investors working out NPLs frequently write loan modifications that reset the rate, term, and balance to create an affordable payment for the borrower. The modified loan is often structured as a new fixed-rate obligation -- sometimes with a step rate that starts lower and increases over two to three years to align borrower and investor interests.

Collateral File Verification

During due diligence, the fixed rate should be confirmed in the original promissory note. Verify that:

• The rate stated in the note matches the rate on the data tape
• No modification has changed the original rate structure
• The loan is not misclassified (some loans labeled "fixed" on data tapes are actually ARMs that have been modified to a fixed rate)

Practical Takeaway

Fixed-rate mortgages are the workhorse of the secondary note market. Their predictable payment structure makes them easy to model, easy to price, and easy to explain to capital partners. Whether you are buying performing notes for cash flow or non-performing notes for workout, understanding the fixed-rate structure is foundational to every deal you evaluate.