Mortgage Rates Index – DEC 29
Tracking the change in price of all mortgage rates
THE LENDZEN INDEX
The LendZen Index tracks the price of mortgage rates across a spectrum of mortgage-backed securities.
Each chart starts at $0 for the first date 🔵 of the time series and measures the rate of change in dollar terms per $100K of loan amount.
The most expensive point in the series is marked with a red 🔴 dot, and the least expensive with a green 🟢 dot.
The measurements in the key box show the total change in price between each colored dot on the index, including high-to-low for descending charts and low-to-high for ascending charts.
MORTGAGE RATES TODAY
The 5-Day change in price is -18 basis points (bps).
The last 24-hour change is -7 bps.
Since December 15, the price of mortgage rates decreased 35 basis points, as seen in the 10-Day chart below.
During the last 30 days (🔵 to 🟡) mortgages have decreased in price by 40 basis points.
The 30-Day chart is useful for spotting trends, plus it gives value to them.
For example, the change in price from the high 🔴 to the low 🟢 was 58 basis points.
This was a change of $2,900 on a $500,000 mortgage.
Since starting the index on May 1, 2025, mortgage rates are now 208 bps less expensive.
The highest price was May 22, and the lowest price was October 21.
INDEX METHODOLOGIES
Most mortgages are sold into mortgage-backed securities (MBS). The price of these bonds determines rates for all banks and lenders.
However, mortgage rates DO NOT rise or fall.
The full range of rates is always available, and instead the price of each rate is what changes.
For example, when mortgage bond prices fall the fee for each rate increases. The same rates exist, but now each is more expensive.
Traditional mortgage indices falsely suggest rates are changing by posting a daily “average” they conjure up from unverifiable data.
Meanwhile, the LendZen Index tracks the price of each mortgage rate across a spectrum of publicly traded MBS.
This provides a clearer picture of how the cost to obtain a mortgage has changed, regardless of the lender, rate, or borrower credit score.
LENDZEN MORTGAGE TREASURY SPREAD
Tracking the “spread” between mortgages and treasury bonds can provide useful perspectives, but only if measured accurately.
There are unique dynamics of mortgage-backed securities, such as prepayment speeds, that are overlooked by the “average rate” indexes.
However, these variables heavily influence how investors allocate to mortgage bonds, and a spread that is calculated without this information has critical flaws that make it unreliable.
The LendZen Mortgage Treasury Spread (LMTS) uses actual bond yields to create a historically consistent, and reliable, data set.
Learn more about spreads in this Substack article.
The LMTS charts below show the spread between mortgage-backed securities and the 10-Year U.S. Treasury Note tightened 1 bps today.
Dec 29 = 0.91 24h = - 1 bps 12m Avg = 1.22 YoY = - 40 bps
LENDZEN MORTGAGE AUTOMATION
In addition to the insights provided by the LendZen Index and the LMTS, you can also check real-time mortgage rates without any human interaction.
LendZen.com (NMLS# 375788) provides a fully automated mortgage shopping experience that gives you anonymous access to all mortgage rates with full transparency of costs upfront as bond prices change.
This eliminates the need for the salespeople who make mortgages so expensive at other lenders.
Some of the unique features you will find on LendZen include:
Customize your own loan in under a minute and get instant qualification results for your exact scenario. Then revisit your real-time options anytime in the future with just one-click – no need to contact a salesperson, reply to “quote threads”, or fill out documents.
Request an official Loan Estimate for the exact pricing you see online with no extra steps.
Refinance loans get an instant BREAKEVEN analysis based on pure math and without any sales bias. The analysis shows you whether a refinance will benefit you and what rate has the most savings, using any timeline you decide.
All of this is at your fingertips when you visit LendZen.com
Really appreciate how this index cuts through the noise of traditional average rate reporting. Watching MBS pricing directly is way more useful than those weekly surveys that lag behind actual market conditions. The 30-day view showing that 58 bps swing is particuarly helpful because it puts real dollar values on the volatility, makes it tangible for people trying to time a refi or purchase. One thing I'm always curious about is how prepayment risk gets priced into these spreads during periods like this where rates are falling. Seems like that would tighten things more than the 1bp we saw today, but maybe the marekt is already anticipating another leg down?