Glossary term
Constant Maturity Treasury (CMT)
A Constant Maturity Treasury rate is a Treasury yield read from the yield curve at a fixed maturity, such as one, five, or ten years.
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What Is a Constant Maturity Treasury?
A Constant Maturity Treasury, or CMT, is a Treasury yield read from the Treasury yield curve at a fixed maturity point, such as one year, five years, or ten years. It is not necessarily the yield on one specific Treasury security.
CMT rates are used as market interest-rate benchmarks. They can appear in adjustable-rate loans, financial contracts, economic analysis, and bond market commentary.
Key Takeaways
- CMT rates are constant-maturity points on the Treasury yield curve.
- They may be derived from the curve rather than from a single outstanding security.
- CMT rates are used as benchmarks in mortgages, loans, contracts, and market analysis.
- They move with Treasury market conditions and the shape of the yield curve.
How CMT Rates Are Built
The Treasury publishes yield curve rates for specified maturities. A constant maturity rate is read at a fixed point on that curve, which makes the series comparable over time even as individual Treasury securities age and roll down the curve.
Rate Type | What It Represents |
|---|---|
1-year CMT | Yield curve rate at a one-year maturity. |
5-year CMT | Yield curve rate at a five-year maturity. |
10-year CMT | Yield curve rate at a ten-year maturity. |
Treasury bill or note yield | Yield on a specific security or auction result. |
Where It Shows Up
Some adjustable-rate mortgages and other loans use a CMT index plus a margin to determine the borrower's rate. Investors also watch CMT rates to understand interest-rate expectations, curve shape, and bond valuation.
Because a CMT is a benchmark, the exact loan or contract rate usually depends on both the index and the spread or margin added to it. A rising CMT can increase floating-rate borrowing costs, while a falling CMT can lower them if the contract allows adjustment.
What to Watch
CMT rates can change as inflation expectations, Federal Reserve policy, growth expectations, Treasury supply, and investor demand change. Shorter maturities often react more directly to policy-rate expectations, while longer maturities can reflect inflation and term-premium views.
Borrowers should read the contract language: reset dates, margins, caps, floors, lookback periods, and the exact index source can all affect payments.
The Bottom Line
A Constant Maturity Treasury rate is a fixed-maturity Treasury benchmark from the yield curve. It is useful because it provides a consistent interest-rate reference, but contracts using it still depend on margins, caps, and reset rules.