How the Treasury Auction Data Is Built

Every US Treasury note, bond and TIPS auction since January 2000 for ten securities: 2-Year Note, 3-Year Note, 5-Year Note, 7-Year Note, 10-Year Note, 20-Year Bond, 30-Year Bond, 5-Year TIPS, 10-Year TIPS and 30-Year TIPS. Each auction carries its stop-out yield, bid-to-cover ratio, offering size, the shares of the competitive award taken by indirect bidders, direct bidders and primary dealers, a link to Treasury's official results and TFTC's demand grade.

Not included: bills, which have their own T-bill rates tracker; floating-rate notes, which are priced on a discount margin instead of a yield; the 20-year TIPS, last sold in 2009; and three off-cycle 2008 reopenings of old 10-year notes that fit no series.

An auction is filed by the term Treasury sold it as, the way the announcement and the market name it. Treasury regularly fills a slot by reopening an older, longer security: the 2-year auction of January 26, 2026 sold more of a 5-year note first issued in 2023, so it sits on the 2-year page.

When the term at auction is a whole number of years, that is the slot. When it is a reopening a few months short of its original term, such as a 9-year 11-month note in the 10-year slot, it goes with its original security, provided it is within two years of it. An original term within six months of a whole year counts as that program, with an exact half year rounding down. Anything further off is skipped.

A refresh runs on weekdays at 10 and 40 minutes past each hour from 15:00 to 18:00 UTC. That brackets the 11:30 am Eastern bill close and the 1:00 pm Eastern note and bond close in both summer and winter time. Each run re-reads the sources and regenerates the hub, every security page, the calendar and both JSON files. Between runs the history is cached for up to six hours and the TreasuryDirect feeds for up to an hour, which is how new announcements reach the pages.

Two automated checks compare the pages with Treasury's own record. Each weekday at 13:00 UTC, every security page must show the newest result Fiscal Data has for it. Each weekday at 19:30 UTC, after the last refresh, every security Fiscal Data lists as auctioned that day must already show that day's result. A miss alerts TFTC the same day.

Each auction is compared with a baseline: the average of the previous six auctions of the same security that carry bidder data. An auction is graded when it has at least 3 such auctions behind it and carries all three measures itself. Three measures are scored against the baseline:

Bid-to-cover

0.15 or more above the baseline scores +1; 0.15 or more below scores −1.

Indirect share

6 percentage points or more above the baseline scores +1; 6 or more below scores −1.

Primary dealer share

Lower is better: 5 percentage points or more below the baseline scores +1; 5 or more above scores −1.

Anything inside a threshold scores zero. Each difference is rounded to six decimal places before the comparison, so a move landing exactly on a threshold counts. The three scores add up to a total from −3 to +3: two or more is Strong, one is Solid, zero is Average, minus one is Soft and minus two or less is Weak.

When the thresholds were set at launch in September 2026, each sat at roughly 0.7 standard deviations of that measure's auction-to-baseline change across every graded auction since 2009, which put about 40% of auctions on Average. Treasury's bidder data starts in 2009, so earlier auctions carry yields and no grade.

The grade does not use the tail, the gap between the stop-out yield and the when-issued yield just before the deadline. When-issued quotes come from the dealer market and Treasury does not publish them, so TFTC does not print tails.

The auction calendarand each security page list the next auction. An auction on TreasuryDirect's upcoming list is shown with its date, and with its size once Treasury announces it. Until an auction reaches that list, the date comes from Treasury's tentative schedule and is marked as tentative, with the schedule's as-of date. The listed date wins as soon as it exists.

A tentative date is dropped once it has passed, and once a listed or held auction of the same security falls within 7 days of it, which covers a date Treasury moved. The site reads Treasury's XML version of the schedule once a day, so a new quarter's calendar appears on its own, and keeps a stored copy for when Treasury's site is unreachable; the current one is “Aug2026 Refunding Auction Calendar Official Ver 2”, as of Aug 19, 2026, with auctions through Jan 28, 2027. The morning check alerts TFTC when the schedule in use is more than 100 days old or its last date has passed.

Every page and file states one update date, taken from the data: the newest auction result it shows, stamped at 19:00 UTC that day, after the 1:00 pm Eastern close in both summer and winter time. The same value is the page's structured-data dateModified, its sitemap lastmod and the dateModified in both JSON files, where updatedThrough gives the bare auction date. The calendar's date is the newest of its latest result, its latest announcement that has happened (stamped at 16:00 UTC) and the tentative schedule's as-of time.

Every figure is re-read from Treasury on each refresh, so a correction Treasury makes shows up on the next run. Changes to sources, classification or the grade are dated in the changelog below. If you find a result that does not match Treasury's official announcement, tell us through the contact page with the auction date and security.

Treasury's figures are public domain. TFTC's compilation and derived measures (the baselines, scores and grades) are free to reuse under CC BY 4.0. Credit:

Source: TFTC (tftc.io/treasury-auctions), data through <date>.

The full history with every baseline and grade is at /treasury-auctions/data.json. The newest result per security, every announced auction and the tentative dates are at /treasury-auctions/latest.json.