Valued September 30, 2026
An open benchmark for the “safe” rate
Eleven open US Treasury total return indices, so that anyone can reproduce and verify.
Free to benchmark against. Paid only to track. No license, no fee and no registration, for any number of portfolios. Naming an index as your benchmark is free too, a prospectus included. A fee applies to one thing: launching a product that tracks one.
| Index | Ticker | Level | Month | Holdings |
|---|---|---|---|---|
| US TreasuryNominal notes and bonds, one year and over | SR-UST-TR | 142.60 | -2.29% | 299 |
| 1-3 Year1 to 3 years | SR-UST-TR-0103 | 132.40 | -0.58% | 96 |
| 3-7 Year3 to 7 years | SR-UST-TR-0307 | 149.55 | -2.08% | 89 |
| 7-10 Year7 to 10 years | SR-UST-TR-0710 | 157.90 | -3.39% | 13 |
| 10-20 Year10 to 20 years | SR-UST-TR-1020 | 145.43 | -4.73% | 61 |
| 20+ Year20 years and over | SR-UST-TR-20PL | 143.42 | -5.38% | 40 |
| 1-3 Month Bill1 to 3 month bills | SR-UST-TR-BILL | 128.42 | +0.30% | 17 |
| 1-12 Month1 to 12 months, bills and aged coupons together | SR-UST-TR-SHRT | 130.37 | +0.24% | 89 |
| Inflation-LinkedInflation-linked, one year and over | SR-UST-TR-TIPS | 171.76 | -2.70% | 48 |
| US Treasury AggregateThe whole marketable market: bills, coupons, linkers and floaters | SR-UST-TR-AGG | 142.10 | -1.52% | 449 |
| Floating RateFloating rate notes | SR-UST-TR-FRN | 131.08 | +0.35% | 8 |
Market value weighted, rebalanced monthly on the last trading day, priced on the END OF DAY column of Treasury's own file. Levels are chained from 100 at each index's base date. The month column is total return over the month ending at this rebalance, and it chains exactly against the level. Holdings runs the other way from the August 31, 2026 rebalance: it is what each index holds now, not what it held through the month that closed.
What $100 became
Base September 30, 2008 to September 30, 2026
Each line is a total-return index based at 100 at its own base date, so it reads directly as what a dollar invested became. The range above starts at that base, one month before the first published level, which is why it precedes the factsheet range for the same index. The floater index starts in December 2014 because floating-rate notes did not exist before then; nothing is rebased to hide that.
Every line starts at 100 on its base date, the month-end before its first published level. The first month plotted is October 2008, in the weeks after Lehman, and it is the reason the linker line drops before it does anything else. Inflation-linked Treasuries returned -8.63% that month as the market priced deflation and forced sellers hit a thin book, against 0.00% for the nominal index over the same month — the whole of that move was the inflation leg, not the rates leg.
Four of the eleven, chosen because they behave differently from one another: the nominal notes and bonds that are most of the market, linkers, floaters and the front end. The five maturity bands track the nominal index closely enough to overplot, and the aggregate is close enough to the nominal index to be a second line along the same path. All six have their own page.
Why an open bond index is unusual
An index priced off licensed marks cannot be given away, because the marks are not the administrator's to give. An index built on a vendor's data and calculated by that vendor inherits the vendor's terms however open its administrator wants to be, and that is the reason open equity indices exist and open bond indices largely do not.
There is no calculation agent here and no licensed input, so there is nobody to pass terms through from. Every input is public and the constituents are published each month, which means the levels can be reproduced rather than trusted. That may be the only way a genuinely open bond index can exist.
Free to benchmark against. Paid only to track. Measuring anything against these indices is free. No license, no fee, no registration, and no permission needed to say that you did. Naming an index as the benchmark of a portfolio, a mandate or a fund, in an investment policy statement, a trustee pack, a client report, a factsheet or a prospectus, is benchmarking. A pension fund whose annual report states that its Treasury sleeve is measured against the Safe Rate US Treasury Index owes us nothing and needs no permission to say it.
A fee applies to one thing: launching a product that tracks an index: an ETF, an index fund, a strategy sold as tracking it, or a structured product whose payoff references it. The test is whether the index is the basis of the product or the yardstick beside it, and in practice it is one word. "Measured against the Safe Rate US Treasury Index" is free in any document. "Tracks the Safe Rate US Treasury Index" is the license.
The point of control is the name, not the numbers. The levels are reproducible by anyone from public data, which is the whole design, so withholding them buys nothing and giving them away costs nothing. What has value is the right to write "tracks" in a prospectus.
| Use | Terms |
|---|---|
| Measure a portfolio, mandate or fund against it | free |
| Name it as your benchmark in an IPS, trustee pack or client report | free |
| Name it as a fund's benchmark in that fund's prospectus | free |
| Receive constituents and returns | free, and derivable from public data anyway |
| Reproduce the index yourself | free, every input is public |
| Launch an ETF, index fund or structured product that tracks it | fee |
| Use the marks in a product's name or branding, or so as to imply we sponsor, endorse or calculate it | license |
Independent evidence
Checked against the funds that follow these bands
Each band is compared against the ETF tracking that part of the market, month by month, using public market prices. The prediction that makes this a test rather than a coincidence is that the gap should be roughly the fee the fund charges: we hold no fee and the fund does, so the fund should trail us by about that much. Figures are stated from the fund's side, so a fund lagging its band is negative. BIL charges 0.1356% a year, so its fee predicts −1.13 basis points a month, and that is the number beside it. Every column is basis points per month except the last.
| Band | Fund | Months | Mean gap, bp | Fee predicts, bp | Median, bp | Worst month, bp | Tracking error, annual |
|---|---|---|---|---|---|---|---|
| US Treasury | GOVT | 175 | -0.68 | -0.93 | -0.11 | +103.32021-12 | 0.64% |
| 1-3 Year | SHY | 215 | -1.28 | -1.25 | -1.18 | -17.12020-05 | 0.14% |
| 3-7 Year | IEI | 215 | -1.18 | -1.25 | -1.13 | -47.72008-11 | 0.27% |
| 7-10 Year | IEF | 215 | -1.05 | -1.25 | -0.99 | +41.42023-11 | 0.44% |
| 10-20 Year | TLH | 215 | -0.52 | -1.25 | -0.72 | +121.92020-03 | 0.86% |
| 20+ Year | TLT | 215 | -0.64 | -1.25 | -0.66 | +125.02023-11 | 1.07% |
| 1-3 Month Bill | BIL | 215 | -1.07 | -1.13 | -1.20 | -27.72008-12 | 0.12% |
| 1-12 Month | SHV | 215 | -0.98 | -1.25 | -1.08 | +15.62008-11 | 0.08% |
| Inflation-Linked | TIP | 215 | -1.46 | -1.50 | -2.20 | +145.02008-12 | 0.65% |
| Floating Rate | TFLO | 141 | -1.57 | -1.25 | -1.73 | +58.22015-12 | 0.28% |
Every gap is negative. Every fund trails its band, which is what holding no fee says should happen. They do not all land on the prediction: 2 sit on it, 1 trail by more than their fee and 7 by less. The widest shortfall is TLH at 0.73 basis points further behind its fee than predicted, and the longest bands are the ones furthest out, which is where premium and discount to net asset value are largest and where a fund's price wanders furthest from what it holds.
A fund is not its index. It trails by its fee and moves either side of fair value, so the number worth reading is the center of two hundred months rather than any single one. The worst-month column is there to show how wide a single observation can be, which is the difference between a comparison and a claim. Tracking error is the standard deviation of that monthly difference, annualised — it measures how far each fund wanders from our band, not how well it tracks its own published benchmark, and it is larger than a fund's own tracking error for exactly that reason.
Expected values are the fee actually in force across each month rather than today's expense ratio, time-weighted over the window. GOVT cut its fee from 0.15% to 0.05% in 2018, so a single ratio would be wrong for most of the history.
Fund prices are public market data. This comparison contains no third-party index values.
IOSCO considerations
The IOSCO Principles for Financial Benchmarks are the standard these indices are built against. No claim of compliance is made: compliance is an assertion an administrator makes about itself, and the governance policy assesses all nineteen principles one at a time and says which are met, which are partial and which are not. The ones worth reading here are where the answer differs from a licensed benchmark's.
Principles 6, 7 and 9: methodology and transparency
Anyone can calculate it, which is the point.
Every input is a public Treasury file, every rule is published, and every holding of every rebalance is on this site with its par, its three float deductions, its prices and its contribution to the month. A reader can recompute a published level from the inputs and check it to floating-point noise. A licensed benchmark cannot offer this at any price, because its inputs are not the reader's to hold.
Principles 10 to 14: data sufficiency and submitters
There is no submitter, so there is nothing to game.
The indices use no submissions, no panel, no expert judgment and no evaluated prices. There is no discretion to exercise and therefore nothing to police: the rules applied to the public file produce one answer. Most of the IOSCO machinery on submitter conduct exists to manage a risk these indices do not carry.
Principle 12: changes to the methodology
Changes are versioned and noticed, not silent.
The rulebook is versioned, every level carries the methodology version that produced it, and changes go through a stated notice period rather than appearing silently. A restatement is republished with its cause rather than overwritten.
Principles 4, 5 and 17: oversight and audit
Anyone outside this firm can look and audit.
Every calculation is reproducible from public data: the inputs are Treasury's own files, the rules are published, and every holding of every rebalance is on this site with the arithmetic that turns it into a level. An auditor needs no access, no license and no cooperation from us to check any figure here, which is not true of a benchmark whose inputs are licensed. Anyone is free to audit these indices. To our knowledge no formal audit has been conducted as of yet.
Principle 8: data quality
Every input is a primary source, published by its issuer.
Every input is a primary source, published by its issuer, and free to anyone. Prices come from the end-of-day file Treasury publishes daily through TreasuryDirect — the statutory prices federal agencies use to value the market based Government Account Series securities they hold, and they appear as such in audited federal financial statements. Amounts outstanding come from the Monthly Statement of the Public Debt, auction results and buyback operations from Treasury Fiscal Data, and Federal Reserve holdings from the New York Fed's System Open Market Account, deducted to reach investable float. No evaluated pricing service, no vendor marks and no licensed data, so anyone can rebuild every number here. What that leaves is a timing difference rather than a data one: our mark is struck near 3:30 PM against an industry that moved to 4:00 PM in 2021, and month-end days run about twice as noisy as mid-month days.
The rules
Fixed-rate nominal notes and bonds with at least one year to final maturity at the rebalance, and a minimum of $300mn float-adjusted. Bills, inflation-linked securities, floaters and STRIPS are excluded from the coupon families, the sibling indices above are those instruments. Market value weighted on amount outstanding as at the start of the month, not at the rebalance that closes it and not today, so a note reopened during the month is not credited with issuance the index did not hold.
Priced on END OF DAY, dirty. Treasury's file publishes three prices per security — BUY, SELL and END OF DAY — and labels none of them as a bid, an ask or a mid. The indices read END OF DAY. Measured against 1.6 million matched quotes from an independent commercial source, 2008 to 2025, it sits closest to the bid side: it is a valuation mark that approximates a bid in aggregate rather than a bid itself, so a reader comparing these levels with a bid-priced administrator should treat the two as close relatives rather than the same convention.
Buybacks are deducted before Federal Reserve holdings, and the two are kept separate. A buyback destroys the debt, at settlement date; the Federal Reserve only parks it. Merging the two adjustments would restore retired par the moment quantitative tightening reversed, which is why they are ordered rather than combined.
Rebalanced on the last trading day of the month, with coupons held as cash until the next reconstitution. A month ending on a bond market holiday uses the last trading day, and a price file with every bid zeroed is rolled back rather than used.
Levels are month-end figures. Curves and prices elsewhere on this site are daily closes, so the September 30, 2026 level sits behind the latest price date by design rather than by staleness, the next level appears at the following rebalance.