Mortgage rates › Methodology
How we source our rate data
Every rate on this site comes from a named source, on a published schedule, with its assumptions stated. This page explains where the numbers come from, what they mean, and — just as importantly — what they can’t tell you.
Last reviewed July 2026 · Marcos Zambrano, NMLS #2187991
Why we show two different rates
If you’ve looked at our 30-year fixed page, you’ve seen two numbers that don’t match. That’s deliberate.
There is no single “mortgage rate.” There are different measurements, published by different organizations, on different schedules, measuring different things. Most rate sites quietly pick one and present it as the rate. We’d rather show you both and explain the gap.
Live lender pricing
Updated daily
An average of what lenders in our network are actively quoting right now. It moves with the bond market and reflects what’s realistically available today.
- Source: Zillow Group mortgage rate data
- Frequency: Refreshed daily; cached on our servers for one hour
- What it is: An average of active lender quotes for a given borrower profile
- What it isn’t: A quote. A commitment. A rate anyone has offered you.
The Freddie Mac benchmark
Updated weekly
The Primary Mortgage Market Survey (PMMS) — the number quoted in almost every news story about mortgage rates. It’s a weekly national average, published every Thursday.
- Source: Freddie Mac PMMS, retrieved via FRED (Federal Reserve Bank of St. Louis), series MORTGAGE30US
- Frequency: Published Thursdays; we refresh within hours of release
- What it is: A lagging weekly average — useful for seeing the trend
- What it isn’t: Current. By Monday, it’s already four days old.
So which one is real?
Both. They measure different things. Live pricing tells you where the market is today; the survey tells you where it’s been this week. When rates are moving quickly, they can differ by a quarter point or more — and that gap is information, not error. If live pricing sits well below the survey, rates have been falling faster than the weekly average has caught up.
What a rate average actually is
This is the part almost nobody explains, and it matters more than the number itself.
An average rate is not a rate anyone was offered. It’s the middle of a distribution of quotes — and every quote in that distribution assumes a specific borrower. Change the borrower and you change the number.
That’s why our rate tables don’t show one number per loan program. They show each program priced for the borrower who actually takes it — and they state the assumptions out loud:
- Conventional — priced at 740+ credit with 20% down, because that’s the borrower conventional lending is built for.
- FHA — priced at under 680 credit with 3.5% down, because pricing FHA at 20% down would be pricing a loan almost nobody takes.
- VA — priced at 0% down, because that’s the entire point of the benefit.
Show all three under one set of assumptions — the way most rate tables do — and you produce numbers that are technically sourced and practically meaningless.
Why some cells are blank
Occasionally a rate table on this site shows a dash instead of a number. We could fill that gap with an estimate. We don’t.
Our live pricing is an average of active lender quotes. When too few lenders are quoting a specific combination — a particular program, at a particular credit tier, at a particular down payment — there isn’t enough data to produce an honest average. Usually that’s because almost nobody takes that loan.
A number built on three quotes looks exactly like a number built on three hundred. That’s precisely what makes it dangerous. We’d rather show you nothing and tell you why.
What these numbers cannot tell you
We want to be direct about the limits of everything on this site.
They are not quotes.
Nothing on this site is an offer of credit, a commitment to lend, or a rate available to you specifically. Rates shown are market averages. Your rate depends on your credit, your down payment, your debt-to-income ratio, the property, the loan amount, the program, and the day you lock.
Credit tiers are wide.
Our data groups borrowers into broad bands. A 660 and a 610 both fall below 680, and they will not be offered the same rate. Any table that pretends otherwise is smoothing over the exact difference you care about.
The advertised rate assumes an ideal borrower.
This is true everywhere, not just here. The headline rate on any lender’s site — including ours — assumes strong credit and a clean file. That’s not a bait and switch. It’s just what an average is. It’s also why we’d rather show you your actual number than argue about whose average is lowest.
How we handle the data
A few technical commitments, for anyone who wants to know:
- We cache on our own servers. Rate data is fetched server-side and stored briefly, so the page loads fast and we’re not hammering a third-party API on every visit.
- We date-stamp everything. Every rate figure on the site carries the date it was last refreshed. If you can’t see when a number was updated, don’t trust it — on any site.
- We fail visibly, not silently. If a data source goes down, we say so. We don’t quietly serve you last week’s number as if it were today’s.
- We don’t editorialize the data. We don’t adjust, smooth, or “correct” the rates we display. Any commentary is clearly labeled as commentary and dated.
Why we bother explaining any of this
Because we’re a broker, not a lender.
A lender has one rate sheet and an incentive to make it look good. We shop your file across more than 40 wholesale lenders, which means we have no attachment to any particular number — and no reason to dress one up.
The honest position is also the useful one: market averages tell you the shape of the market. They cannot tell you your rate. The only thing that can is running your actual file.
That’s what the rest of this site is for.
Written and reviewed by Marcos Zambrano
Owner, Andes Mortgage LLC · NMLS #2187991 · Licensed mortgage broker since 2013 · Background in mathematics and finance
Andes Mortgage is licensed in Georgia, Florida, Texas, South Carolina, and Alabama. Business-purpose investment loans, including DSCR, are available in most other states.
Questions about our data or our methodology? Ask us directly — we’ll answer.
Averages are the market. Let’s find your number.
Answer a few questions and we’ll show you which programs you fit and what rate range you’re realistically looking at. No credit pull, no phone call required.