---
ticker: "USTSY3M"
title: "U.S. Treasury 3M Constant Maturity Yield"
unit: "%"
frequency: "Daily"
source: "Nelson and Siegel (1987); Gürkaynak, Sack, and Wright (2007)"
release: "Updated Daily"
category: "Yield Curve & Inflation Compensation"
country: "US"
language: "en"
canonical: "https://kred.dev/en/series/USTSY3M"
license: "https://creativecommons.org/licenses/by-nc-nd/4.0/"
latest_value: 4.22
latest_date: "2026-10-22"
first_date: "1981-09-01"
observations_total: 11285
observations_shown: 120
---

# U.S. Treasury 3M Constant Maturity Yield

## Overview

A three-month Treasury yield at the money-market end of the curve, and the short leg of the ten-year spread published alongside it.

## Key Figures

|  | Value | Date |
|---|---|---|
| Latest | 4.22 | 2026-10-22 |
| Change from previous | -0.03 | 2026-10-21 |
| Change over one year | +0.26 | 2025-10-22 |
| Highest on record | 17.01 | 1981-09-01 |
| Lowest on record | 0.00 | 2008-12-10 |
| Period covered | 1981-09-01 – 2026-10-22 |  |
| Observations | 11285 |  |

## Recent observations

| Date | Value | Change |
|---|---|---|
| 2026-05-01 | 3.68 | 0.00 |
| 2026-05-04 | 3.70 | +0.02 |
| 2026-05-05 | 3.69 | -0.01 |
| 2026-05-06 | 3.69 | 0.00 |
| 2026-05-07 | 3.69 | 0.00 |
| 2026-05-08 | 3.69 | 0.00 |
| 2026-05-11 | 3.70 | +0.01 |
| 2026-05-12 | 3.70 | 0.00 |
| 2026-05-13 | 3.69 | -0.01 |
| 2026-05-14 | 3.69 | 0.00 |
| 2026-05-15 | 3.69 | 0.00 |
| 2026-05-18 | 3.68 | -0.01 |
| 2026-05-19 | 3.67 | -0.01 |
| 2026-05-20 | 3.65 | -0.02 |
| 2026-05-21 | 3.68 | +0.03 |
| 2026-05-22 | 3.68 | 0.00 |
| 2026-05-26 | 3.68 | 0.00 |
| 2026-05-27 | 3.68 | 0.00 |
| 2026-05-28 | 3.69 | +0.01 |
| 2026-05-29 | 3.69 | 0.00 |
| 2026-06-01 | 3.78 | +0.09 |
| 2026-06-02 | 3.77 | -0.01 |
| 2026-06-03 | 3.78 | +0.01 |
| 2026-06-04 | 3.78 | 0.00 |
| 2026-06-05 | 3.78 | 0.00 |
| 2026-06-08 | 3.80 | +0.02 |
| 2026-06-09 | 3.79 | -0.01 |
| 2026-06-10 | 3.79 | 0.00 |
| 2026-06-11 | 3.78 | -0.01 |
| 2026-06-12 | 3.78 | 0.00 |
| 2026-06-15 | 3.79 | +0.01 |
| 2026-06-16 | 3.79 | 0.00 |
| 2026-06-17 | 3.83 | +0.04 |
| 2026-06-18 | 3.83 | 0.00 |
| 2026-06-22 | 3.85 | +0.02 |
| 2026-06-23 | 3.85 | 0.00 |
| 2026-06-24 | 3.85 | 0.00 |
| 2026-06-25 | 3.84 | -0.01 |
| 2026-06-26 | 3.83 | -0.01 |
| 2026-06-29 | 3.87 | +0.04 |
| 2026-06-30 | 3.87 | 0.00 |
| 2026-07-01 | 3.85 | -0.02 |
| 2026-07-02 | 3.82 | -0.03 |
| 2026-07-06 | 3.87 | +0.05 |
| 2026-07-07 | 3.86 | -0.01 |
| 2026-07-08 | 3.87 | +0.01 |
| 2026-07-09 | 3.83 | -0.04 |
| 2026-07-10 | 3.85 | +0.02 |
| 2026-07-13 | 3.89 | +0.04 |
| 2026-07-14 | 3.84 | -0.05 |
| 2026-07-15 | 3.83 | -0.01 |
| 2026-07-16 | 3.84 | +0.01 |
| 2026-07-17 | 3.85 | +0.01 |
| 2026-07-20 | 3.86 | +0.01 |
| 2026-07-21 | 3.87 | +0.01 |
| 2026-07-22 | 3.89 | +0.02 |
| 2026-07-23 | 3.95 | +0.06 |
| 2026-07-24 | 3.96 | +0.01 |
| 2026-07-27 | 3.96 | 0.00 |
| 2026-07-28 | 3.90 | -0.06 |
| 2026-07-29 | 3.83 | -0.07 |
| 2026-07-30 | 3.82 | -0.01 |
| 2026-07-31 | 3.83 | +0.01 |
| 2026-08-03 | 3.91 | +0.08 |
| 2026-08-04 | 3.89 | -0.02 |
| 2026-08-05 | 3.89 | 0.00 |
| 2026-08-06 | 3.90 | +0.01 |
| 2026-08-07 | 3.87 | -0.03 |
| 2026-08-10 | 3.89 | +0.02 |
| 2026-08-11 | 3.89 | 0.00 |
| 2026-08-12 | 3.87 | -0.02 |
| 2026-08-13 | 3.87 | 0.00 |
| 2026-08-14 | 3.86 | -0.01 |
| 2026-08-17 | 3.87 | +0.01 |
| 2026-08-18 | 3.86 | -0.01 |
| 2026-08-19 | 3.86 | 0.00 |
| 2026-08-20 | 3.87 | +0.01 |
| 2026-08-21 | 3.88 | +0.01 |
| 2026-08-24 | 3.87 | -0.01 |
| 2026-08-25 | 3.86 | -0.01 |
| 2026-08-26 | 3.85 | -0.01 |
| 2026-08-27 | 3.84 | -0.01 |
| 2026-08-28 | 3.90 | +0.06 |
| 2026-08-31 | 3.91 | +0.01 |
| 2026-09-01 | 3.92 | +0.01 |
| 2026-09-02 | 3.92 | 0.00 |
| 2026-09-03 | 3.89 | -0.03 |
| 2026-09-04 | 3.91 | +0.02 |
| 2026-09-08 | 3.94 | +0.03 |
| 2026-09-09 | 3.95 | +0.01 |
| 2026-09-10 | 4.00 | +0.05 |
| 2026-09-11 | 4.07 | +0.07 |
| 2026-09-14 | 4.11 | +0.04 |
| 2026-09-15 | 4.11 | 0.00 |
| 2026-09-16 | 4.14 | +0.03 |
| 2026-09-17 | 4.12 | -0.02 |
| 2026-09-18 | 4.14 | +0.02 |
| 2026-09-21 | 4.17 | +0.03 |
| 2026-09-22 | 4.16 | -0.01 |
| 2026-09-23 | 4.19 | +0.03 |
| 2026-09-24 | 4.24 | +0.05 |
| 2026-09-25 | 4.24 | 0.00 |
| 2026-09-28 | 4.28 | +0.04 |
| 2026-09-29 | 4.25 | -0.03 |
| 2026-09-30 | 4.20 | -0.05 |
| 2026-10-01 | 4.17 | -0.03 |
| 2026-10-02 | 4.19 | +0.02 |
| 2026-10-05 | 4.22 | +0.03 |
| 2026-10-06 | 4.21 | -0.01 |
| 2026-10-07 | 4.22 | +0.01 |
| 2026-10-08 | 4.23 | +0.01 |
| 2026-10-09 | 4.25 | +0.02 |
| 2026-10-13 | 4.26 | +0.01 |
| 2026-10-14 | 4.28 | +0.02 |
| 2026-10-15 | 4.28 | 0.00 |
| 2026-10-16 | 4.26 | -0.02 |
| 2026-10-19 | 4.27 | +0.01 |
| 2026-10-20 | 4.26 | -0.01 |
| 2026-10-21 | 4.25 | -0.01 |
| 2026-10-22 | 4.22 | -0.03 |

## Definition

USTSY3M is the raw series that records the three-month U.S. Treasury constant maturity yield exactly as published, in percent per annum and without any transformation. A constant maturity yield is read at a fixed remaining maturity from a fitted yield curve, so the value is not the yield of any particular outstanding security.

What is read is a par yield, the single discount rate equating a security's remaining cash flows to a price of par, which is the yield-to-maturity construct of Macaulay (1938), and a level that decomposes into the average short rate expected over the term plus a premium (Hicks 1939). A curve of this kind may be summarized by a parametric level-slope-curvature form and its second-term extension (Nelson and Siegel 1987; Svensson 1994), or recovered as a discount function by cubic and exponential splines and by the refinement for differential coupon taxation (McCulloch 1971, 1975; Vasicek and Fong 1982). Bliss (1997) sets those estimators against one another, and a daily construction of the class is specified by Gürkaynak, Sack, and Wright (2007). KRED neither fits the curve nor interpolates the maturity point, and the fitting method behind the published value is not restated here.

A par curve is not the zero-coupon term structure that underlies the duration measure of Fisher and Weil (1971), so the recorded value is not a spot rate and is a different object from the zero-coupon and forward curves KRED estimates elsewhere. At three months the level sits close to the average overnight rate expected over a term that spans roughly one meeting cycle. The rate being expected is an operating target, whose corridor and standing-facility mechanics Bindseil (2004) sets out.

## Methodology

KRED applies no transformation to USTSY3M and stores the published constant maturity yield exactly as recorded, with no rescaling, deflating, smoothing, annualizing, or differencing, and it neither fits the curve nor interpolates the maturity point. What follows is therefore the measurement basis by which such a value comes to exist rather than a procedure KRED carries out.

A par yield is the single discount rate equating a security's coupons and principal to a price of par (Macaulay 1938), and the timing of those cash flows is summarized by the zero-coupon-based duration of Fisher and Weil (1971). Inside one year the securities involved are discount instruments carrying no coupon, so their quoted yields enter such a fit on a coupon-equivalent basis. A three-month point sits among the most frequently refreshed short maturities on the curve. Recovering a continuous discount function from observed prices proceeds by cubic spline, by its refinement for differential coupon taxation, or by exponential splines (McCulloch 1971, 1975; Vasicek and Fong 1982), while parametric construction instead imposes a level-slope-curvature form or its forward-rate extension (Nelson and Siegel 1987; Svensson 1994). A daily version of that class, producing par, zero-coupon, and forward rates at any maturity, is specified by Gürkaynak, Sack, and Wright (2007), and the estimators are evaluated against one another by Bliss (1997).

Fits of this kind are commonly estimated from off-the-run prices, since an issue trading special in the secured financing market prices richer than the curve, a specialness defined by Duffie (1996). The identity tying a fitted par curve to expected future short rates and a term premium is that of Hicks (1939).

## Applications in Economics

At the money-market end the premium for so short a commitment is small, so the level is close to the average overnight rate expected over the term, which is the decomposition of Hicks (1939). That rate is an operating target, whose corridor and standing-facility mechanics are set out by Bindseil (2004) and whose design across operating frameworks is surveyed by Borio (1997), and it is steered day to day in the manner modelled by Bartolini, Bertola, and Prati (2002) and determined as characterized by Hamilton (1996). Three months spans roughly one meeting cycle, so the level moves when the next decision is repriced.

Front-end government yields also move with secured funding, since collateral and specialness set repo below the general riskless rate in the framework of Duffie (1996). Read across maturities on the common yield concept of Macaulay (1938), this level fixes the front of the slope and curvature of a fitted form (Nelson and Siegel 1987; Svensson 1994; Gürkaynak, Sack, and Wright 2007), and it discounts near-dated cash flows through the discount function of McCulloch (1971).

## Applications in Financial Markets

In fixed-income practice this level is the discount rate for near-dated cash flows, and the rate sensitivity it implies is the duration of Macaulay (1938) in the zero-coupon-consistent form of Fisher and Weil (1971). At three months the point is the standard reference against which short funding and bill positions are marked.

Relative value is judged against a fitted curve, and the fit may be a spline discount function or its tax-adjusted variant (McCulloch 1971, 1975), an exponential spline (Vasicek and Fong 1982), or a parametric form with its extension (Nelson and Siegel 1987; Svensson 1994), so what looks cheap on one fit need not look cheap on another (Bliss 1997).

Positions are financed in the secured market, where collateral and specialness set the repo rate below the general riskless rate (Duffie 1996), and the forward rates implied by the curve price the carry and roll-down on the holding (Hicks 1939; Gürkaynak, Sack, and Wright 2007).

## Statistical Tests

On the 11,223 daily observations spanning 1981-09-01 to 2026-07-24, fit with a constant and trend, the unit-root battery does not agree, so no clean order of integration is assigned to the three-month constant-maturity Treasury par yield. The augmented Dickey-Fuller test of Dickey and Fuller (1979), in the lag-augmented form of Said and Dickey (1984), fails to reject a unit root at p = 0.2064, and the Kwiatkowski et al. (1992) stationarity test rejects its trend-stationary null at p < 0.01, so the opposite-null pair concurs against stationarity, while the nonparametric Phillips and Perron (1988) test is the sole dissenter and rejects the unit root at p = 0.013. That lone dissent is the documented Phillips-Perron over-rejection toward spurious stationarity under near-unit moving-average errors (Ng and Perron 2001), so the concurring reading leans against stationarity and the disagreement is reported rather than resolved. The GLS-detrended escalation of Elliott, Rothenberg, and Stock (1996) was run for this ambiguous outcome and fails to reject a unit root with a statistic of −0.697651 at p = 0.927338, which under the house protocol confirms the ADF leg alone and never enters as a fourth vote, so it cannot lift the verdict to a clean order.

The mean-shift and serial-correlation diagnostics are run on the first difference, the object the protocol fixes for an observed daily level, since a break search or a portmanteau on a level that may carry a stochastic trend would spuriously segment and read near-unit autocorrelations (Bai and Perron 1998; Perron 1989). The multiple-break procedure of Bai and Perron (1998), computed by the dynamic-programming algorithm of Bai and Perron (2003), finds no break in the mean of the differenced series, consistent with the parameter-instability inference of Andrews (1993). The Ljung and Box (1978) portmanteau statistic, refining the original Box and Pierce (1970) form, rejects the white-noise null on the first difference at lags 10 and 20, with Q = 249.615 and Q = 440.879 and p = 0.000 in both cases, and the automatic portmanteau test of Escanciano and Lobato (2009) also rejects, with a statistic of 4.0841 at p = 0.0432886, a rejection that sits just inside the 5 percent level.

The series is daily and has no low-integer seasonal period, so the seasonal-unit-root machinery of Hylleberg et al. (1990) and the Canova and Hansen (1995) seasonal-stationarity test are not applicable and are deliberately not run, the degeneracy of the seasonal auxiliary regression at a daily period being the standard ground (Beaulieu and Miron 1992; Ghysels and Osborn 2001).

## Frequently Asked Questions

### What are US Treasury constant-maturity yields?

United States Treasury constant-maturity par yields at the standard tenors, read from a fitted curve rather than from any individual issue's quote and carried as published.

### Are US Treasury constant-maturity yields the same as zero-coupon rates?

No. They are par yields, corresponding to hypothetical bonds paying coupons out to the stated maturity, and the zero-coupon rate is a different object that does not take the same value.

### Is any maturity in the US Treasury yield panel interpolated?

No. Six months is an observed constant-maturity point in this panel. The six-month point in the Korean government bond group is interpolated because no benchmark issue exists there, so the two must not be read the same way.