Treasury bond

912810QK7 · 3.875% due August 15, 2040

Original term
30-Year
Maturity
Aug 15, 2040
Coupon
3.875%
Pays
Semi-Annual
Dated
Aug 15, 2010
First coupon
Feb 15, 2011
Priced through
Sep 10, 2026
Analyzed through
Sep 10, 2026

Statement of August 31, 2026

Amount outstanding
$43.21bn
Held stripped
$527.4m
Share stripped
1.22%

Stripped par is held as separate interest and principal components rather than as whole securities. The Safe Rate indices deliberately do not deduct it, and the whole-market figure is published so that decision can be argued with. Market statistics.

Amount outstanding as reported by Treasury, in its Monthly Statement of the Public Debt. The Safe Rate indices weight on a different figure, float-adjusted original par, and the two are not comparable security by security. The index figures are published per holding.

Risk, September 10, 2026

Yield to maturity
5.174%
Modified duration
10.334 yr
DV01
0.0904
Convexity
131.893
Dirty price
87.503

Where its rate sensitivity sits

3M
6M
1Y
2Y
3Y
5Y
7Y
10Y
15Y
20Y
25Y
30Y
Sensitivity to a one basis point move at each point on the curve, in years. Concentrated in 9 of twelve buckets, summing to 10.543 years against a modified duration of 10.334.

Against the fitted curve

Priced 3.0 bp rich to the curve on that day, 27.50 cents per 100 of face.

That is -2.74 standard deviations from its own typical residual.

Yield to maturity, 4,019 observations

0%1%2%3%4%5%6%Aug 16, 2010Sep 10, 2026Aug 16, 2010Yield to maturity3.722%Dec 29, 2010Yield to maturity4.415%May 11, 2011Yield to maturity4.329%Sep 21, 2011Yield to maturity3.018%Feb 6, 2012Yield to maturity3.031%Jun 15, 2012Yield to maturity2.635%Oct 26, 2012Yield to maturity2.821%Mar 14, 2013Yield to maturity3.155%Jul 25, 2013Yield to maturity3.569%Dec 6, 2013Yield to maturity3.833%Apr 22, 2014Yield to maturity3.417%Sep 2, 2014Yield to maturity3.084%Jan 20, 2015Yield to maturity2.324%Jun 1, 2015Yield to maturity2.905%Oct 9, 2015Yield to maturity2.852%Feb 25, 2016Yield to maturity2.416%Jul 7, 2016Yield to maturity1.984%Nov 17, 2016Yield to maturity2.914%Apr 3, 2017Yield to maturity2.903%Aug 14, 2017Yield to maturity2.700%Dec 26, 2017Yield to maturity2.739%May 9, 2018Yield to maturity3.108%Sep 19, 2018Yield to maturity3.198%Feb 5, 2019Yield to maturity2.952%Jun 18, 2019Yield to maturity2.397%Oct 29, 2019Yield to maturity2.206%Mar 13, 2020Yield to maturity1.357%Jul 24, 2020Yield to maturity0.992%Dec 7, 2020Yield to maturity1.389%Apr 20, 2021Yield to maturity2.056%Aug 30, 2021Yield to maturity1.703%Jan 12, 2022Yield to maturity2.069%May 25, 2022Yield to maturity3.075%Oct 6, 2022Yield to maturity4.023%Feb 22, 2023Yield to maturity4.025%Jul 5, 2023Yield to maturity4.064%Nov 14, 2023Yield to maturity4.744%Mar 28, 2024Yield to maturity4.364%Aug 8, 2024Yield to maturity4.204%Dec 20, 2024Yield to maturity4.732%May 5, 2025Yield to maturity4.719%Sep 16, 2025Yield to maturity4.414%Jan 30, 2026Yield to maturity4.597%Jun 11, 2026Yield to maturity4.754%Sep 10, 2026Yield to maturity5.174%

Price history

4,019 trading days to Sep 10, 2026

80100120140160Aug 16, 2010Sep 10, 2026Aug 16, 2010Close102.750Dec 29, 2010Close91.125May 11, 2011Close92.500Sep 21, 2011Close116.438Feb 6, 2012Close116.031Jun 15, 2012Close124.531Oct 26, 2012Close120.219Mar 14, 2013Close113.156Jul 25, 2013Close105.281Dec 6, 2013Close100.688Apr 22, 2014Close107.906Sep 2, 2014Close114.063Jan 20, 2015Close129.781Jun 1, 2015Close117.250Oct 9, 2015Close118.125Feb 25, 2016Close126.844Jul 7, 2016Close136.094Nov 17, 2016Close116.375Apr 3, 2017Close116.406Aug 14, 2017Close120.031Dec 26, 2017Close119.063May 9, 2018Close112.250Sep 19, 2018Close110.594Feb 5, 2019Close114.625Jun 18, 2019Close124.406Oct 29, 2019Close127.719Mar 13, 2020Close144.781Jul 24, 2020Close152.313Dec 7, 2020Close142.688Apr 20, 2021Close128.875Aug 30, 2021Close135.063Jan 12, 2022Close127.750May 25, 2022Close111.094Oct 6, 2022Close98.125Feb 22, 2023Close98.125Jul 5, 2023Close97.688Nov 14, 2023Close90.031Mar 28, 2024Close94.313Aug 8, 2024Close96.188Dec 20, 2024Close90.594May 5, 2025Close90.875Sep 16, 2025Close94.156Jan 30, 2026Close92.406Jun 11, 2026Close91.000Sep 10, 2026Close87.219
The most recent 20 trading days of prices for 912810QK7.
DateBidOfferClose
Sep 10, 202687.65687.59487.219
Sep 9, 202688.17288.09488.313
Sep 8, 202688.70388.65688.531
Sep 4, 202688.78188.71988.656
Sep 3, 202688.92288.87588.688
Sep 2, 202688.46988.40688.438
Sep 1, 202688.75088.68888.438
Aug 31, 202688.71988.65688.750
Aug 28, 202689.32889.25089.000
Aug 27, 202689.54789.50089.375
Aug 26, 202689.51689.46989.406
Aug 25, 202689.59489.53189.594
Aug 24, 202689.18889.12589.000
Aug 21, 202688.73488.68888.625
Aug 20, 202688.95388.90689.031
Aug 19, 202689.31389.25089.406
Aug 18, 202688.51688.46988.563
Aug 17, 202688.62588.56388.375
Aug 14, 202688.82888.78188.781
Aug 13, 202689.26689.21989.250

Prices are per 100 of face, from Treasury's own end-of-day file. A dash in the bid or offer column means none was posted that day.

3 auctions

A CUSIP can be auctioned more than once: Treasury reopens an existing security rather than issuing a new one, so the same bond is sold again at whatever yield the market then wants.

Auction history for 912810QK7.
Auction dateIssuedTypeOfferedAcceptedBid to coverHigh yield
Aug 12, 2010Aug 16, 2010New issue$16.0bn$17.0bn2.77x3.954%
Sep 9, 2010Sep 15, 2010Reopening$13.0bn$13.1bn2.73x3.820%
Oct 14, 2010Oct 15, 2010Reopening$13.0bn$13.1bn2.49x3.852%

The curve this was priced against →

Index levels before September 30, 2026 are back-tested. They were computed after the fact by applying the rules to historical data, which benefits from hindsight in the choice of rules, and an index cannot be invested in directly. Methodology v1.0 takes effect at that rebalance, when levels begin to be struck on the day; the rulebook is identical either way, and the version is published on every row.

A fitted curve is a fit, not a quote. Daily error averages 3.8 basis points across the history and reaches about 20 on the worst days, in December 2008, when the market was genuinely hard to fit one smooth curve to. Every curve page publishes its own fit error rather than burying it.

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Safe Rate™, Safe Rate Indices™ and the Safe Rate US Treasury Index™ are trademarks of Safe Rate, claimed through use in commerce and not registered. Third-party marks are the property of their owners, which are not affiliated with and do not endorse this data.

Curves are fitted from public Treasury data and carry fit error; figures are not a record of trading, and an index cannot be invested in directly. No claim of compliance with the IOSCO Principles for Financial Benchmarks is made or implied. Not investment advice, not an offer, and not a recommendation to buy or sell any security.