How Treasury auctions work, and why markets watch them
The US government borrows by auctioning bills, notes and bonds on a published schedule. Here is how the auctions run, what bid-to-cover and tails mean, and how individuals can take part.
The United States government borrows by selling securities, and nearly all of that selling happens through auctions run by the Treasury Department's Bureau of the Fiscal Service. Several auctions happen every week. Most pass without notice, but a weak result can move interest rates across the economy, which is why traders and financial reporters follow them closely.
What is sold
Treasury marketable securities come in a few families:
- Bills mature in one year or less. They pay no coupon; they are sold at a discount to face value, and the difference is the interest.
- Notes mature in 2, 3, 5, 7 or 10 years and pay a fixed coupon every six months.
- Bonds mature in 20 or 30 years and also pay semiannual coupons.
- TIPS, Treasury Inflation-Protected Securities, adjust their principal with the Consumer Price Index.
- Floating rate notes mature in two years and pay interest that resets with the 13-week bill rate.
Savings bonds, such as Series I and EE bonds, are separate. They are not auctioned and cannot be traded.
The schedule
Treasury aims to be regular and predictable, a policy it calls regular and predictable issuance. It publishes a tentative auction schedule months in advance. A few days before each auction it issues an announcement giving the offering amount, the auction date, the issue date and other terms. After the auction, usually within minutes, it publishes the results.
Each quarter, Treasury also releases a refunding statement explaining how it expects to adjust auction sizes over the coming months. Markets watch this closely because larger auction sizes mean more supply for investors to absorb.
How bidding works
There are two kinds of bids.
Noncompetitive bids agree to accept whatever rate the auction sets. They are guaranteed to be filled, up to a limit of $10 million per bidder for most securities. Individuals buying through TreasuryDirect or through many brokers bid this way.
Competitive bids specify the yield or discount rate the bidder is willing to accept. Large investors, including banks, asset managers, foreign central banks and primary dealers, bid competitively. A single bidder cannot be awarded more than 35% of the offering amount through competitive bids.
Treasury first fills all noncompetitive bids. It then accepts competitive bids starting from the lowest yield and moving up until the offering is fully sold. The highest accepted yield is called the high yield or stop-out rate. Every winning bidder, competitive and noncompetitive, receives that same rate. This is known as a single-price or uniform-price auction, a format Treasury has used for all its marketable securities since 1998.
Primary dealers
Primary dealers are banks and securities firms that trade directly with the Federal Reserve Bank of New York. As part of that role, they are expected to bid in every Treasury auction in reasonable amounts. Their bids act as a backstop: if demand from other investors is weak, dealers end up buying a larger share, which they then try to sell into the market.
Reading the results
A few numbers in the results release get most of the attention.
- High yield. The rate set by the auction. Analysts compare it with where the security was trading just before the deadline, a level often called the when-issued yield.
- Tail. If the high yield comes in above the when-issued level, the auction is said to have tailed. A tail means the government had to offer a higher rate than the market expected to sell the full amount, a sign of soft demand. An auction that clears below the when-issued yield is said to have stopped through.
- Bid-to-cover ratio. Total bids divided by the amount sold. A ratio of 2.5 means bidders asked for two and a half times as much as was offered. Higher generally signals stronger demand, though the ratio is best compared with recent auctions of the same security.
- Allotments. Results show how much went to primary dealers, direct bidders and indirect bidders. Indirect bidders, who submit bids through an intermediary, include foreign central banks. A high dealer share often suggests other buyers held back.
Why a weak auction matters
Treasury yields are benchmarks. The 10-year yield, for example, strongly influences mortgage rates, and short-term bill rates track the Federal Reserve's policy rate. When an auction tails, it can push yields higher across the market for that day as traders reassess demand. A run of weak auctions can raise borrowing costs for the government and, indirectly, for households and companies.
The government never fails to sell its offering, because competitive bids at some yield always cover it. The question each auction answers is the price.
How individuals can buy
Individuals can bid noncompetitively through TreasuryDirect, the government's website, with no fees, or through a bank or brokerage account. Securities bought at auction can be held to maturity, in which case the investor receives the full face value, or, if held at a brokerage, sold in the secondary market before maturity at whatever the market price is. TreasuryDirect accounts cannot sell directly in the market; holdings must first be transferred to a broker.
Interest on Treasury securities is subject to federal income tax but exempt from state and local income taxes, which can make them attractive to savers in high-tax states.
The bottom line
Treasury auctions are the plumbing of federal borrowing. They run on a public calendar, use a simple uniform-price format and release their results almost immediately. A few numbers, the tail, the bid-to-cover and who bought, tell you whether demand for US debt was strong or soft that day.
This article is general information, not investment advice.