Housing & Real Estate
How Mortgage Rates Work — What Drives Rates Up and Down
Mortgage rates are driven by the 10-year Treasury yield, inflation expectations, and the mortgage-backed securities market — not the federal funds rate directly.
Mortgage rates are the interest rates charged on home loans. They affect the largest financial decision most Americans make and have ripple effects across construction, consumer spending, and financial services. Understanding what drives rates helps executives anticipate market shifts.
What Drives Mortgage Rates
The primary driver of fixed mortgage rates is the 10-year Treasury yield. Mortgage-backed securities (MBS) compete with Treasuries for investor capital, so mortgage rates maintain a spread above the 10-year yield — typically 1.5 to 2.5 percentage points. When the 10-year yield rises, mortgage rates follow.
The federal funds rate has an indirect effect. It influences short-term rates and adjustable-rate mortgages more directly. Fixed-rate mortgages respond to long-term inflation expectations and economic outlook rather than the current fed funds rate. This is why mortgage rates sometimes rise even when the Fed cuts rates.
The MBS Spread
The spread between mortgage rates and the 10-year Treasury yield is driven by: prepayment risk (borrowers refinancing when rates drop), credit risk, servicing costs, and investor demand for MBS. During the pandemic, the Fed purchased MBS aggressively, compressing the spread to historic lows. As the Fed stopped buying (and began selling) MBS, the spread widened, pushing mortgage rates higher even relative to Treasury yields.
Types of Mortgage Products
The three main products tracked by Freddie Mac are the 30-year fixed (most popular — stable payments for 30 years), 15-year fixed (lower rate, higher payments, faster equity), and 5/1 ARM (fixed for 5 years, then adjusts annually). Each serves different borrower needs and risk profiles.
Impact on Housing and the Economy
Mortgage rates directly affect housing affordability, home sales volume, housing starts (new construction), and home prices. A 1 percentage point rate increase reduces purchasing power by approximately 10-12%. Elevated rates create a "lock-in effect" where homeowners with low-rate mortgages refuse to sell, constraining inventory and supporting prices even as demand falls.
Related Indicators
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All Guides →Fed Funds Rate Explained
The federal funds rate is the interest rate banks charge each other for overnight loans. It's the Federal Reserve's primary tool for controlling inflation and influencing the economy.
Yield Curve Explained
The yield curve plots Treasury bond yields across different maturities. When it inverts (short-term rates exceed long-term rates), it has historically predicted every U.S. recession.
Primary Sources
Frequently Asked Questions
Why don't mortgage rates follow the fed funds rate exactly?
Fixed-rate mortgages are driven primarily by the 10-year Treasury yield and mortgage-backed securities (MBS) market, not the fed funds rate. The fed funds rate influences short-term borrowing costs and ARMs. Long-term rates reflect inflation expectations and economic outlook — which don't always move with short-term policy rates. Mortgage rates can rise even when the Fed cuts rates if inflation expectations increase.
What is a normal mortgage rate?
The historical average for the 30-year fixed mortgage rate since 1971 is approximately 7.7%. Rates below 5% are historically unusual — the sub-3% rates of 2020-2021 were the result of extraordinary pandemic monetary policy. Current rates in the 6-7% range are below the long-term average.
What is the mortgage lock-in effect?
The lock-in effect occurs when homeowners with low mortgage rates (e.g., 3% from 2020-2021) refuse to sell because moving would mean taking on a new mortgage at much higher rates (e.g., 6.5%+). This keeps existing home inventory low, supports home prices, and reduces transaction volumes — creating challenges for homebuyers, real estate agents, and mortgage lenders.