30Y Mortgage Rate vs 30Y Treasury Yield

The Bankrate national-average 30Y fixed APR was 6.46 percent on April 28, 2026 (note: the underlying par rate Bankrate reports the same week was 6.40 percent; the 6 basis point gap is points and origination fees baked into the APR). The 30Y Treasury yield was approximately 4.92 percent (FRED DGS30 April 2026 monthly average), sitting above the 10Y Treasury at 4.31 percent (the 30Y to 10Y term-structure premium ran ~60 basis points across the month). The mortgage-APR-to-30Y spread is therefore ~154 basis points.

For context against the conventional mortgage-to-10Y spread (more commonly cited): 6.46 percent minus 4.31 percent equals 215 basis points. The mortgage-to-10Y spread is wider because the comparison ignores the fact that prepayment optionality shortens MBS effective duration well below the stated 30 years. The 30Y-to-30Y comparison is duration-cleaner: both legs nominally mature in 30 years; the spread isolates the option-adjusted spread plus credit and liquidity premia.

The dominant published mortgage-Treasury reference uses the 10Y Treasury as the benchmark. That convention exists because effective MBS duration historically clusters near the 10Y point on the curve once prepayment optionality is priced. The convention is useful for trader-level comparisons but loses information about the term-structure component of the spread.

Using the 30Y Treasury as the benchmark holds nominal maturity equal at 30 years on both legs. The remaining spread is the cleanest available measure of three components: (1) the option-adjusted spread compensating MBS investors for negative convexity from the prepayment option; (2) credit and servicing premium for non-Treasury credit risk and operational overhead; (3) a small liquidity premium because TBA MBS trade actively but with less daily volume than 30Y Treasuries. Spread changes can then be decomposed into curve-slope versus OAS effects in a way the 10Y-benchmarked spread cannot support.

Every US 30Y fixed mortgage carries a free embedded call option: the borrower can refinance at any time without penalty. From the MBS investor side, this is a short call position. The investor receives a premium (the spread above the Treasury) in exchange for accepting that principal will be returned faster than scheduled when rates fall and slower than scheduled when rates rise. This is the textbook definition of negative convexity.

The practical cost: borrowers pay roughly 75 to 100 basis points more on a 30Y mortgage than they would for an equivalent loan without the prepayment right. That premium funds the OAS that MBS investors require. The current ~154 basis point mortgage-APR-to-30Y spread breaks down approximately as 80 to 100 basis points option-adjusted spread plus 40 to 60 basis points credit and servicing plus a small liquidity premium. When mortgage rates fall sharply, OAS widens because faster prepayments destroy MBS yield; when rates rise sharply, OAS widens because slower prepayments extend MBS duration into a rising-rate environment. The spread is therefore non-linear in interest rates, which is the defining characteristic of MBS as an asset class.

TCW research from January 2026 reports current-coupon MBS convexity at minus 3.3, the most negative reading recorded since the metric began being tracked systematically in the early 2000s. For comparison, normal MBS convexity ranges between minus 1.0 and minus 2.0; the 2007 to 2008 housing peak saw readings near minus 2.5; the post-COVID 2021 to 2022 episode saw readings near minus 2.8.

Minus 3.3 means a 100 basis point parallel rate move produces an asymmetric MBS price response: rallies are blunted by accelerated prepayments removing high-coupon paper, while sell-offs are amplified by extension that lengthens duration into the rising-rate environment. The Janus Henderson 2026 outlook described 2025 as the best MBS year since 2002, with 6.5 percent coupons that started 2025 with three-year duration shortening to one-year duration by year-end as prepayments accelerated. That single dynamic explains why mortgage rates have not fallen alongside Treasury yields: MBS investors require incremental compensation for taking on convexity risk that has gotten meaningfully worse, and they pass that requirement back through to the primary mortgage rate.

Approximately 70 percent of outstanding US mortgage debt carries a coupon below 5 percent, the legacy of 2020 to 2021 refinance activity at sub-3.5 percent rates. The current 6.46 percent rate environment means moving to a similar-priced home with a new mortgage costs roughly 50 percent more in monthly payment than continuing to pay the existing mortgage on the existing home. The decision to move is therefore deferred indefinitely for a meaningful share of homeowners.

The consequence is that existing-home sales transaction volume has run at multi-decade lows. The October 2025 NAR Housing Affordability Index was 106.2, just above the 100 level that marks the median family being able to qualify for the median home, with the median existing-home sales price at $420,600. Affordability for buyers is barely above the threshold; affordability for would-be sellers contemplating a move is far below it. The pair captures this in real time: the spread cannot tighten meaningfully without either (1) the Fed restarting MBS QE, (2) bank Treasury portfolio expansion absorbing MBS supply, or (3) sustained mortgage rate decline below 5.5 percent triggering a refinance wave that resets the convexity profile.

The mortgage-Treasury spread peaked near 290-300 basis points (NY Fed Staff Report 674; Brookings) in the late-2008 post-Lehman MBS market dislocation. The proximate cause was severe loss of TBA MBS liquidity: dealers pulled bids, hedge funds liquidated MBS portfolios into a thin market, and bank balance sheets refused new MBS allocations through year-end.

The spread compressed dramatically once the Fed initiated MBS QE with the Agency MBS Purchase Program: $1.25 trillion of MBS was purchased between January 5, 2009 and March 31, 2010 (Federal Reserve Board figures). By the end of 2010 the spread had compressed back into normal-conditions territory near 150 to 180 basis points (Freddie 30Y minus 10Y UST). The compression was not driven by Treasury yield movement; it was driven by the Fed becoming the price-insensitive marginal MBS buyer. The episode established the modern playbook: any mortgage market dislocation can be addressed by Fed MBS purchases, and the Fed has used that tool again in March 2020 (COVID emergency) and continues to provide implicit floor support.

From 2009 through mid-2022, the Fed accumulated agency MBS that peaked near $2.7 trillion (Federal Reserve), becoming the single largest holder of US mortgage-backed securities. That price-insensitive demand compressed the mortgage-to-10Y spread to a 130 to 160 basis point range across most of the 2010s, near the lower end of the pre-2008 norm. Mortgage rates were structurally cheap during this era because of the Fed bid.

The Fed began QT in June 2022 with an initial MBS roll-off cap of $17.5 billion per month, doubling to $35 billion per month in September 2022 (Richmond Fed Q3 2022). The withdrawal of the marginal price-insensitive buyer is a primary driver of the post-2022 spread widening into the 180 to 220 basis point range (mortgage-to-10Y benchmark). Bank portfolio MBS holdings have not fully replaced Fed demand because banks themselves face tighter capital and liquidity requirements that disincentivize MBS accumulation. The Janus Henderson 2026 outlook noted that increased GSE demand and bank demand should help support spreads going forward, but the structural ceiling on spread compression appears to be roughly 150 basis points (mortgage-to-10Y benchmark) or roughly 130 basis points (30Y benchmark), still above pre-2008 norms.

A median-priced home of $420,600 (NAR October 2025) with a 20 percent down payment ($84,120) finances $336,480 over 30 years at the 6.46 percent APR. The monthly principal-and-interest payment is approximately $2,114. Add property tax (assumed 1.0 percent of home value annually = $350 per month) and homeowners insurance ($150 per month estimate) and the all-in monthly housing cost is roughly $2,614.

The equivalent calculation at a hypothetical 4.5 percent mortgage APR (the level that would prevail with a 130 basis point 30Y-vs-30Y spread against a 3.2 percent 30Y Treasury) produces a monthly P&I of roughly $1,705, all-in monthly cost roughly $2,205. The difference is roughly $409 per month or about $4,900 annually for the same home. NAR's October 2025 Housing Affordability Index of 106.2 means the median family income of approximately $98,000 is just barely sufficient to qualify for the median home; a 100 basis point reduction in the mortgage rate would push affordability toward the 130 to 140 range, the historical norm for healthy housing markets.

Three pathways could compress the mortgage-to-30Y spread by 100 basis points or more from the current ~154 basis point level.

Pathway one: Fed restarts MBS QE. This requires a recession or financial-stress event that forces the Fed back into emergency mode. A 100 basis point compression would take 12 to 24 months of $25 to $35 billion monthly MBS purchases. The trigger is not a discretionary policy choice; it requires a stress event meaningful enough to override the Fed's post-2022 reluctance to expand the balance sheet.

Pathway two: Sustained mortgage-rate decline below 5.5 percent triggers a refinance wave. A wave of refinancing into lower-coupon production would reset MBS convexity from minus 3.3 toward more normal minus 1.5 to minus 2.0 levels, reducing the OAS demanded by investors. This pathway is self-reinforcing: lower rates trigger refis, refis improve convexity, improved convexity tightens spreads, tighter spreads further reduce mortgage rates. The catalyst is typically Fed rate cuts of 100 to 150 basis points combined with a broader rate rally.

Pathway three: Banks materially expand MBS portfolios. The Janus Henderson 2026 outlook flagged this as constructive but it requires regulatory capital and liquidity rule changes that are not currently planned. Bank MBS demand absent regulatory change is unlikely to provide more than 30 to 50 basis points of compression on its own.

The mortgage-to-Treasury spread is one of the most sensitive real-time indicators of US housing-finance system stress. Spread above 250 basis points historically correlates with material MBS market dysfunction (2008-2009 peak near 290-300bp; March 2020 brief spike). Spread of roughly 180 to 220 basis points (mortgage-to-10Y) reflects elevated convexity stress without market dysfunction — the post-QT environment. Spread of 150 to 180 basis points reflects normal post-QT functioning. Spread below 150 basis points reflects either active Fed QE support or unusually benign rate volatility.

The pair updates with daily Bankrate mortgage data and minute-level Treasury data. Watch for spread widening of 30 basis points or more over a 5-day period as a leading indicator of MBS stress. The 2008 episode produced ~200 basis points of spread widening over 8 weeks; the March 2020 episode produced ~100 basis points over 2 weeks before Fed intervention. Spread widening in the absence of an obvious stress catalyst is often more informative than the rate level itself, because it implies the marginal MBS investor is exiting before the underlying stress driver becomes visible in headline indicators.

Most likely scenario (45 percent): Fed continues gradual easing. Mortgage-APR-to-30Y spread compresses gradually toward 130 to 140 basis points as Fed cuts 50 to 75 basis points and the convexity profile improves modestly. Mortgage APR falls toward 5.85 to 6.05 percent. Affordability index moves to 115 to 120, still below historical norms but materially improved. Existing-home sales recover meaningfully but remain below pre-2022 transaction volumes.

Recession scenario (25 percent): Fed cuts ~200 basis points. 30Y Treasury falls toward the high-3 percent range. Mortgage rate falls to ~5.50 percent on a stable spread. Refinance wave begins, improving MBS convexity and producing a self-reinforcing spread compression. Affordability index moves above 130. Housing transaction volume recovers to normal levels within 18 to 24 months.

Sticky inflation scenario (20 percent): Fed pauses or hikes 25 basis points. 30Y Treasury rises through 5 percent. Mortgage APR rises to ~6.85 percent. Lock-in effect intensifies; existing-home sales drop to fresh multi-decade lows. Affordability index falls toward 95.

MBS stress scenario (10 percent): Fed restarts MBS QE in response to a financial-system event. Spread compresses sharply by 50 to 80 basis points within 6 months. Mortgage APR falls below 5.50 percent. The path through stress to lower mortgage rates is volatile and not guaranteed to deliver the expected affordability improvement if the underlying stress event also damages household balance sheets.