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. For an inflation-linked security the difference is mostly inflation rather than float: Treasury reports what a holder is owed today, which includes the uplift shown as the index ratio above, while the index keeps original par and carries the uplift in the price. The index figures are published per holding.
Inflation-linked measures, September 30, 2026
An inflation-linked security prices off a real curve, so its yield is a real yield, a return above inflation rather than in cash terms, and its principal is indexed. The figures below are in REAL terms unless labeled otherwise.
Real yield
3.379%
Index ratio
1.2988
Real duration
21.941 yr
DV01
0.1092
Convexity
5.08
Real clean price
49.719
Accrued (real)
0.032
Real dirty price
49.751
Indexed principal
129.881
Money clean price
64.575
The index ratio is a multiplier, not a percentage: 1.2988 means the principal is worth that many times its original face today. So the real clean price of 49.719 is not what a buyer pays , multiply by the ratio to get 64.575 per 100 of original face.
Against the fitted real curve
Priced 3.6 bp rich to the real curve on that day, 39.30 cents per 100 of face.
That is 0.84 standard deviations from its own typical residual.
Real yield, 1,651 observations
Price history
1,651 trading days to Sep 30, 2026
The most recent 20 trading days of prices for 912810SM1.
Date
Bid
Offer
Close
Sep 30, 2026
49.891
49.844
49.719
Sep 29, 2026
49.953
49.906
50.125
Sep 28, 2026
50.281
50.219
50.281
Sep 25, 2026
50.813
50.750
50.938
Sep 24, 2026
51.500
51.438
51.156
Sep 23, 2026
52.344
52.281
52.031
Sep 22, 2026
53.234
53.188
53.188
Sep 21, 2026
53.250
53.188
53.438
Sep 18, 2026
52.781
52.719
52.625
Sep 17, 2026
53.000
52.938
53.156
Sep 16, 2026
53.094
53.031
52.656
Sep 15, 2026
52.797
52.750
52.750
Sep 14, 2026
53.141
53.094
53.000
Sep 11, 2026
53.203
53.125
52.844
Sep 10, 2026
53.375
53.313
52.969
Sep 9, 2026
53.734
53.656
53.875
Sep 8, 2026
54.281
54.219
54.125
Sep 4, 2026
54.078
54.000
54.063
Sep 3, 2026
54.359
54.313
54.063
Sep 2, 2026
53.875
53.813
53.844
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.
2 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.
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.
Free to benchmark against. Paid only to track. Measuring anything against these curves and indices is free. No license, no fee, no registration, and no permission needed to say that you did, including in a prospectus. A fee applies to one thing: launching a product that tracks an index.
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.