Treasury auctions: how the US sells its debt and how to read results

The US Treasury raises almost all of its borrowing by auction. Every week it sells bills, and every month it sells notes and bonds, to whoever bids: banks, dealers, pension funds, foreign central banks and individuals with a TreasuryDirect account. The auction decides the interest rate the government pays, so in a very direct sense the market, not Treasury, sets the cost of federal debt.

Auctions also give the market a regular look at demand. Traders read the results within minutes of release: the yield the auction cleared at, how many bids came in for each dollar sold, and who ended up holding the securities. A weak result can move yields across the whole curve the same afternoon.

This page explains the rules (single-price, sealed-bid auctions with competitive and noncompetitive bids), walks through a toy auction and a real one from May 2024 line by line, and shows how to read the numbers analysts quote. The securities themselves are described on Treasury bills, notes and bonds: the US government’s debt menu.

The life of an auction

TreasuryDirect describes four steps: announce, hold the auction, bid, and issue. Market practice adds a fifth that happens in between.

1. Announcement. Ahead of each auction, Treasury publishes the security, the offering amount, the auction, issue and maturity dates, and the closing times for noncompetitive and competitive bids. A tentative schedule months ahead lets investors plan; 4-week bills, for example, are typically announced on a Tuesday, auctioned on the Thursday and issued the following Tuesday.
2. When-issued trading. From the announcement until the security is issued, dealers trade it on a "when-issued" basis: a contract to buy or sell the new security once it exists. A New York Fed study of July 2019 to June 2020 found when-issued trading averaged $80 billion a day, about 12% of all Treasury trading, and noted that it helps price discovery before the auction.
3. The auction. Bids are sealed and submitted electronically before the closing time.
4. Results. Treasury releases the high yield, the bid-to-cover ratio and the breakdown of who bid and who was awarded, on auction day.
5. Settlement. On the issue date buyers pay and receive the securities, in a TreasuryDirect account or through a bank or broker.

Regular schedules mean auctions arrive like clockwork: bills of 4, 6, 8, 13, 17 and 26 weeks weekly and 52-week bills every four weeks; 2-, 3-, 5- and 7-year notes monthly; 10-year notes and 20- and 30-year bonds as new issues four times a year with reopenings in the other months; and two-year FRNs as new issues in January, April, July and October.

Competitive and noncompetitive bids

There are two ways to bid, and they serve very different bidders.

Noncompetitive bids say, in effect, "I will take whatever yield the auction sets." They are limited to $10 million per bidder per auction. TreasuryDirect accounts can only bid this way. Because Treasury accepts all valid noncompetitive bids before any competitive ones, a noncompetitive bidder is certain to receive the full amount.

Competitive bids state the yield (or, for bills, the discount rate) the bidder will accept. A bidder can submit several. They are placed through a bank, broker or dealer, or directly by institutions with access to Treasury's auction system. Treasury will not recognize more than 35% of the offering amount at any single yield from one bidder, and it will not let a bidder's net long position plus its awards exceed 35% of the offering. These limits keep any single buyer from cornering a new issue.

How the auction clears: a toy example

Why would anyone bid 4.50% if they end up getting 4.54% anyway? Because a low bid is nearly certain to be filled, and under the single-price rule bidding low does not cost the bidder anything: the clearing yield is set by the marginal bid. That makes it safer for bidders to bid what they truly value the security at, which is a common argument for the single-price design.

Reading real results: the 13-week bill of May 20, 2024

Here is the Treasury press release for one ordinary auction, a 91-day bill, with each line explained.

The release states the ratio directly: $202,037,006,400 ÷ $70,000,758,400 = 2.89. Bidders asked for nearly three times what was on offer. SOMA, the Federal Reserve's portfolio, is listed separately and left out of that ratio.

The release also splits the competitive awards by type of bidder:

• Primary dealers are the 25 firms (as listed by the New York Fed) that act as the Fed's trading counterparties. They are required to bid for their pro-rata share of every auction at reasonably competitive prices, which is why they always tender large amounts. In the release they are bidding for their own house accounts.
• Direct bidders are other firms bidding for their own accounts.
• Indirect bidders are customers bidding through a direct submitter, including foreign and international monetary authorities bidding through the New York Fed.

Analysts read a high indirect share as strong end-investor demand and a high dealer share as a sign that dealers had to absorb what others didn't want. In this auction, dealers submitted 71% of competitive bids but received only 36% of the awards: other buyers took most of the bill.

Tails and stop-throughs

Because the new security trades when-issued before the auction, the market knows roughly where it "should" clear. Comparing the auction's high yield with the when-issued yield just before bidding closes gives a quick read of demand. This comparison is market convention, not a statistic Treasury publishes.

• Tail: the high yield comes in above the when-issued yield. Treasury had to accept higher yields than the market expected to sell the full amount, which suggests soft demand.
• Stop-through: the high yield comes in below the when-issued yield. Bidders competed hard enough to clear the auction at a richer price than expected.

A tail of a basis point or two is common and usually forgotten by the next day. Larger tails, especially combined with a low bid-to-cover and a high dealer share, can push yields higher across the curve because they suggest that buyers need a better price to absorb new supply.

Why auctions matter beyond the bond market

The government's deficits determine how much must be auctioned; see Government debt and deficits: how US federal borrowing works. When issuance grows, the market must absorb more securities at every maturity. If demand doesn't keep pace, yields have to rise until buyers appear, and higher long-term yields feed directly into mortgage rates, corporate borrowing costs and stock valuations (see How interest rates affect stocks: discount rates and equity duration). That is why big auctions, particularly 10- and 30-year sales, are watched by stock traders as well as bond traders.

The mix of maturities matters too. Financing more through bills keeps auctions small at the long end but means the debt must be rolled over sooner. Selling more long bonds locks in rates for decades but adds to the supply that long-term investors must absorb.

Pitfalls and limitations

• One auction is one data point. Bid-to-cover and tails vary from auction to auction for technical reasons: holidays, the size of the offering, what else is being sold that week. Compare with recent auctions of the same security.
• Bid-to-cover counts bids, not commitment. Dealers are obliged to bid on every auction, often at yields they don't expect to win, which inflates tendered amounts.
• Indirect is not the same as foreign. The indirect category includes foreign central banks but also domestic investment managers bidding through dealers.
• Tails depend on when you measure. The when-issued yield moves right up to the deadline, and different sources use different reference times.
• Auction yields are not market yields. After the auction the security trades in the secondary market, and its yield changes from there.

Auction measures compared

How Finabase does it

Finabase doesn't publish an auction calendar or auction results, and it has no Treasury-auction page. You can still watch how the market trades around auctions.

• The Treasury yields list and maturity pages such as the 10-year let you look at a chart on the day of a large auction and see how yields moved.
• Treasury futures for 2-, 10- and 30-year maturities in the futures list trade nearly around the clock and often react first to a surprising result.
• The Fed news topic collects rate-related headlines, which often include auction coverage.

The auction diagram on this page was drawn by Finabase Research, and the worked results come from Treasury's own press release.

Frequently asked questions

How does a Treasury auction work?

Treasury announces the security and amount, collects sealed bids until a deadline, fills all noncompetitive bids first, and then fills competitive bids from the lowest yield upward until the offering is sold. Every winner receives the same yield, the highest one accepted.

What is a good bid-to-cover ratio?

There is no fixed threshold; it depends on the security. Analysts compare each result with recent auctions of the same maturity. The 13-week bill auction of May 20, 2024 drew a ratio of 2.89, meaning bids of $2.89 for each $1 sold.

Can individuals buy at a Treasury auction?

Yes. Individuals can bid noncompetitively through a TreasuryDirect account, up to $10 million per auction, or through a bank or broker. Noncompetitive bids are filled in full at the auction's yield.

What does it mean when an auction tails?

It means the auction cleared at a higher yield than the when-issued market was trading at just before the bidding deadline. Treasury had to pay more than expected, so traders read it as weaker demand.

Who are indirect bidders?

Indirect bidders are customers who place competitive bids through a direct submitter such as a primary dealer. They include foreign and international monetary authorities bidding through the New York Fed, as well as other institutional investors.

Summary

Treasury sells its debt in single-price, sealed-bid auctions. Noncompetitive bids up to $10 million are filled first at whatever yield the auction sets; competitive bids are filled from the lowest yield up, subject to 35% limits, and every winner receives the same highest accepted yield. The results tell the market how much demand there was and from whom: in the 13-week bill auction of May 20, 2024, bids of $202 billion chased $70 billion of bills for a bid-to-cover of 2.89, and indirect bidders took 57.5% of the competitive awards. Tails, stop-throughs, dealer and indirect shares add context, but each auction is one data point best compared with recent sales of the same security.