Mortgage Rates vs. Bond Yields: Why Is the Gap So Wide?

The 10-year Treasury yielded 5.17% in late September 2026, while the 30-year mortgage index stood at 7.43%. See how Treasury, municipal, corporate and mortgage bonds compare—and why the spread between bond yields and your mortgage rate matters.

The Rate Update with Dan Frio

Bond Yields and Mortgage Rates: What’s the Spread?

The 10-year Treasury is at 5.17%. The 30-year mortgage index is at 7.43%. Here is the simple connection—and what the difference means for your payment.

As of late September 2026. Yields and mortgage rates change daily.

Bond yields, at a glance

These examples show government, state/local municipal, corporate and mortgage bonds. The 10-year Treasury is the key mortgage comparison because many 30-year loans are paid off or refinanced in roughly seven to ten years.

Bond or rateYield / rate
1-month Treasury bill4.04%
3-month Treasury bill4.24%
6-month Treasury bill4.33%
1-year Treasury4.50%
2-year Treasury4.81%
5-year Treasury4.98%
10-year Treasury5.17%
20-year Treasury5.54%
30-year Treasury5.49%
10-year AAA municipal bond (state/local, generally federal tax-free)3.72%
30-year AAA municipal bond4.87%
AAA corporate bond index5.70%
BBB corporate bond index6.08%
BB high-yield corporate bond index6.64%
B high-yield corporate bond index7.87%
Fannie Mae 30-year mortgage bond (MBS) current coupon6.10%
Ginnie Mae 30-year MBS current coupon6.05%
30-year fixed mortgage index (borrower rate)7.43%

Treasuries: September 25, 2026. AAA municipal bonds and MBS current coupons: September 21, 2026. Corporate index yields: September 24, 2026. Mortgage News Daily rate index: September 25, 2026. These different dates and instruments are comparisons, not directly interchangeable investments.

The spread between the 10-year and mortgage rates

The spread is simply the mortgage rate minus the 10-year Treasury yield. It reflects mortgage-bond investor costs and risks, plus the costs and margins between the bond market and a borrower’s loan.

Normal historical spread · 2000–2019 average
~1.70 points

5.17% Treasury + 1.70 points = ~6.87%

Late September 2026 spread
~2.26 points

5.17% Treasury + 2.26 points = 7.43%

What to tell your audience: At the same 5.17% Treasury yield, a normal historical spread points to about 6.87% instead of 7.43%. The roughly 0.56-point difference is in the spread. This is an illustration, not an available loan quote or a prediction.

Mortgage payment calculator

Enter a home price and down payment to see estimated principal and interest. Tap either spread example to compare the monthly payment using the same 10-year Treasury yield.

Estimated monthly principal & interest$2,222.17
Loan amount
$320,000.00
Total interest over selected term
$479,980.50

Estimate excludes property taxes, homeowners insurance, mortgage insurance, HOA dues and closing costs. The two preset rates are market illustrations, not loan offers.

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Sources

U.S. Treasury yields: Forbes Advisor, Treasury Rates, September 25, 2026. Mortgage rate and 10-year comparison: Mortgage News Daily, September 25, 2026. AAA municipal bonds and agency MBS current coupons: Raymond James Weekly Interest Rate Monitor, September 21, 2026. Corporate index effective yields: ICE BofA indices via FRED, September 24, 2026. Typical spread: approximate 2000–2019 average supplied for this article.

* Specific loan program availability and requirements may vary. Please get in touch with your mortgage advisor for more information.