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, October 20, 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
3.198%
Index ratio
1.3015
Real duration
21.936 yr
DV01
0.1138
Convexity
5.07
Real clean price
51.813
Accrued (real)
0.046
Real dirty price
51.858
Indexed principal
130.148
Money clean price
67.433
The index ratio is a multiplier, not a percentage: 1.3015 means the principal is worth that many times its original face today. So the real clean price of 51.813 is not what a buyer pays , multiply by the ratio to get 67.433 per 100 of original face.
Against the fitted real curve
Priced 4.2 bp rich to the real curve on that day, 47.43 cents per 100 of face.
That is -0.20 standard deviations from its own typical residual.
Real yield, 1,664 observations
Price history
1,664 trading days to Oct 20, 2026
The most recent 20 trading days of prices for 912810SM1.
Date
Bid
Offer
Close
Oct 20, 2026
51.766
51.688
51.813
Oct 19, 2026
51.500
51.438
51.156
Oct 16, 2026
51.984
51.906
51.813
Oct 15, 2026
51.750
51.656
51.563
Oct 14, 2026
50.516
50.438
50.844
Oct 13, 2026
50.469
50.375
50.375
Oct 9, 2026
49.969
49.906
49.875
Oct 8, 2026
49.641
49.563
49.969
Oct 7, 2026
49.219
49.156
49.406
Oct 6, 2026
49.719
49.656
49.594
Oct 5, 2026
49.359
49.281
49.281
Oct 2, 2026
49.844
49.781
49.656
Oct 1, 2026
49.875
49.813
49.875
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
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.