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How a mortgage rate is set

By Samprit Biswas, editor · Updated October 8, 2026

No one publishes the rate you will be offered: a lender prices your loan on the day you apply. But each step of that price can be seen in public data, and our estimate follows the steps in order, from the average prime offer rate (APOR), an annual percentage rate (APR) published each week.

Today's 30-year fixed purchase estimate, step by step
  1. APOR, the week of Oct 5, 20267.37% APR
  2. Moved with the 10-year Treasury yield since7.38% APR
  3. Priced for 760–779 credit, 20% down7.43% APR
  4. The rate, at 1.21 points7.31% rate

Estimate, not an offer · FFIEC, week of Oct 5, 2026 · Fannie Mae, dated Sep 30, 2026 · U.S. Treasury, Oct 7, 2026

Sources and licences
Average prime offer rates (FFIEC)

Average prime offer rates published by the FFIEC for the Consumer Financial Protection Bureau; a U.S. government work in the public domain.

Loan-level price adjustments (Fannie Mae)

Borrower adjustments derived from Fannie Mae's Loan-Level Price Adjustment Matrix dated September 30, 2026. Fannie Mae does not endorse these estimates.

Daily Treasury par yield curve (U.S. Treasury)

10-year par yield from the U.S. Department of the Treasury's daily par yield curve rates.

The anchor: APOR

Each week the Federal Financial Institutions Examination Council publishes the average prime offer rate (APOR): the APR lenders offered a borrower with excellent credit and a large down payment, from a survey of their offers. It is public, it is the same across the country, and it is where our estimate starts. Each week's rate applies from its Monday.

The daily move: the 10-year Treasury

APOR changes once a week, but mortgage rates move every day. Between weeks, our estimate moves with the 10-year Treasury yield, by the share of each move APOR has followed over the past few years. Mortgage rates and the 10-year Treasury shows how closely.

Your adjustment: credit and down payment

APOR prices one borrower. Fannie Mae charges every other borrower a fee set by credit score and down payment, its loan-level price adjustment. Turned into rate, the difference from APOR's borrower moves the estimate up, or for a few borrowers down. Credit score and down payment draws every pair.

From the APR to the rate

APOR is an APR, so our estimate starts as one too. The rate beside it is the note rate at the points the survey's loans typically paid, which is why it sits below the APR. See Rate vs. APR and Discount points.

What a lender adds

A lender prices your whole file: the property, the county, the loan's size, your income and debts, and its own costs and appetite that day. Our estimate knows your credit, your down payment and the product. Treat it as a fair starting point, and ask lenders for Loan Estimates for the real price.

See today's rate for your details

How to cite this page

InfinityRateWatch. "How a mortgage rate is set." https://infinityratewatch.com/learn/how-a-mortgage-rate-is-set/. Data as of Oct 8, 2026.