The Interplay of Treasury Yields, Inflation Expectations, and MBS Demand in Sustaining Elevated Mortgage Rates

The U.S. housing market in 2025 continues to grapple with persistently elevated mortgage rates, a phenomenon deeply rooted in the complex dynamics of the bond market. At the heart of this situation lies a triad of interrelated forces: Treasury yields, inflation expectations, and mortgage-backed securities (MBS) demand. These elements, shaped by Federal Reserve policy and broader economic conditions, have created a self-reinforcing cycle that sustains high borrowing costs for homeowners.

Treasury Yields: The Anchor of Mortgage Rates

Treasury yields serve as a foundational benchmark for mortgage rates, reflecting investor sentiment about inflation, growth, and monetary policy. As of November 2025, Treasury yields across the 2-year, 5-year, and 10-year maturities have declined, while the 30-year yield remains unchanged. This divergence highlights evolving market expectations, with futures markets pricing in a 25 basis point rate cut at the December 2025 Federal Reserve meeting. However, the 10-year Treasury yield is projected to remain rangebound between 3.75% and 4.25% through 2026, driven by cautious Fed policy and inflation that, though moderating, remains above the 2% target.

The Federal Reserve's dual mandate-price stability and maximum employment-continues to constrain aggressive rate cuts. Even as inflation eases, the central bank's reluctance to signal a pivot has kept Treasury yields elevated, indirectly supporting mortgage rates. For instance, the 30-year mortgage rate averaged 6.79% in Q2 2025, a modest decline from earlier in the year but still significantly higher than pre-pandemic levels.

Inflation Expectations: A Double-Edged Sword

Inflation expectations play a critical role in shaping Treasury yields and, by extension, mortgage rates. The spread between nominal Treasury yields and Treasury Inflation-Protected Securities (TIPS) yields provides a real-time gauge of market inflation forecasts. In mid-2024, this spread indicated an expected inflation rate of 2.1% over the next decade. While this suggests moderation compared to the peak inflationary pressures of 2022–2023, it remains above the Federal Reserve's long-term target.

The Federal Reserve Bank of Cleveland's inflation expectation models further underscore this dynamic, integrating data from Treasury yields, inflation swaps, and surveys to project long-term inflation trends. These models highlight how even modest upward revisions in inflation expectations can pressure Treasury yields higher, creating a ripple effect on mortgage rates. For example, if investors anticipate a resurgence in inflation due to shifting trade policies or supply chain disruptions, they demand higher yields to compensate for purchasing power erosion-a mechanism that directly impacts mortgage borrowing costs.

MBS Demand: A Policy-Driven Lever

The demand for mortgage-backed securities (MBS) has historically been a key determinant of mortgage rates, with the Federal Reserve's quantitative easing (QE) and tightening (QT) policies acting as primary levers. During the 2015–2025 period, the Fed's large-scale MBS purchases narrowed the yield spread between Treasuries and mortgages. However, the shift to quantitative tightening (QT) in 2022 reversed this dynamic, widening the spread to over 3 percentage points. This widening persisted through 2025 as the Fed gradually reduced its MBS holdings while maintaining a presence in the Treasury market.

The result has been a steeper yield curve and elevated mortgage rates. By May 2025, Treasury yields had risen, exacerbating the cost of mortgage financing. While the primary-secondary spread is expected to narrow if Treasury yields decline, this outcome remains contingent on Fed policy and inflation trajectories. The Fed's cautious approach to MBS purchases-stepping back from direct market intervention-has left mortgage rates more exposed to broader bond market volatility.

The Symbiotic Cycle: Why Rates Remain High

The interplay between these three factors creates a self-sustaining cycle. Elevated Treasury yields, driven by inflation expectations and Fed policy, anchor mortgage rates. Meanwhile, reduced MBS demand-stemming from QT-limits downward pressure on mortgage rates, even as Treasury yields fluctuate. This dynamic is further amplified by the Fed's reluctance to signal a clear policy pivot, which keeps market uncertainty high and yields elevated.

For investors, this environment underscores the importance of monitoring inflation indicators, Fed communications, and MBS market activity. A narrowing of the Treasury-MBS yield spread, for instance, could signal improved mortgage rate conditions, but such outcomes depend on a delicate balance of policy and market forces.

Conclusion

Elevated mortgage rates in 2025 are not an isolated phenomenon but a product of interconnected bond market dynamics. Treasury yields, inflation expectations, and MBS demand form a triad that sustains high borrowing costs, with the Federal Reserve's policy trajectory acting as both a stabilizer and a wildcard. As the Fed navigates the delicate task of balancing inflation control with economic growth, investors and homeowners alike must remain attuned to these evolving dynamics.