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Read a Treasury auction's bid-to-cover ratio as a measure of the amount bid relative to the amount awarded under the published calculation. Read High Yield as the auction's clearing yield for a Treasury note or bond. One describes bidding volume relative to supply; the other identifies the yield at which the auction finished filling that supply.
Neither number, on its own, tells you whether the result beat market expectations. For that, you need a comparable auction history and, for a yield surprise, a correctly timed pre-auction market quote.
| Measure | Question it helps answer | What it does not establish |
|---|---|---|
| Bid-to-cover | How much was tendered relative to the amount accepted in the published ratio? | The number of investors or the next market move |
| High Yield | What was the highest successful competitive yield for this note or bond? | Whether the result was unexpectedly high or low |
| Auction tail or stop-through | How did the clearing yield compare with the same security's when-issued yield at auction close? | A guaranteed return after the auction |
The definitions and examples below use Treasury's auction results, its auction glossary, and the New York Fed's explanation of auction comparisons.
What does bid-to-cover measure?
The ratio compares amounts of securities bid for and awarded, not a count of bid forms or people. A ratio of 2.41 means approximately $2.41 was tendered for each $1 accepted within that calculation's scope. It does not mean 2.41 investors competed for each security.
For the official release used here:
Bid-to-cover = Subtotal tendered ÷ Subtotal accepted
Those Subtotal figures combine the competitive, noncompetitive and FIMA noncompetitive rows. They exclude the separately listed SOMA amounts. Use the release's bid-to-cover footnote to identify the right inputs rather than assuming its bottom-line Total is the denominator.
A dated example: the May 28, 2024 two-year note auction
Treasury's result for CUSIP 91282CKS9 shows the following amounts in U.S. dollars:
| Category | Tendered | Accepted |
|---|---|---|
| Competitive | $165,295,145,000 | $68,286,045,000 |
| Noncompetitive | $710,972,800 | $710,972,800 |
| FIMA noncompetitive | $3,000,000 | $3,000,000 |
| Subtotal used for bid-to-cover | $166,009,117,800 | $69,000,017,800 |
| SOMA | $4,096,369,900 | $4,096,369,900 |
| Total including SOMA | $170,105,487,700 | $73,096,387,700 |
$166,009,117,800 ÷ $69,000,017,800 = approximately 2.4059, reported as 2.41.
Dividing the two bottom-line Totals instead gives approximately 2.33, which is not this auction's published ratio. Dividing only the competitive amounts gives a different measure, too. The exact footnote removes that ambiguity. This is a historical worked example, not a report on today's auction. Treasury's May 28, 2024 result
Why distinguish FIMA and SOMA?
FIMA refers to Foreign and International Monetary Authorities. In this release, the FIMA noncompetitive row is inside the Subtotal used for coverage. You should not remove it merely because it is an official-sector category.
SOMA is the Federal Reserve's System Open Market Account. Its Treasury rollovers use noncompetitive tenders that add to the announced auction size. The New York Fed's rollover FAQ explains that these tenders receive the auction's clearing terms rather than setting them. In the dated result above, SOMA is outside both inputs to the published bid-to-cover calculation.
This distinction also prevents double counting. The separate dealer, direct-bidder and indirect-bidder breakdown on the release divides the competitive row into categories; it is not an additional set of bids to add to the Subtotal.
What does High Yield mean in a Treasury auction?
For notes and bonds, High Yield is the highest competitive yield at which Treasury makes awards. It is often called the stop-out yield or clearing yield. Higher submitted yields that receive no award are excluded from this field.
The word “high” refers to that auction cutoff. It does not label the security as a speculative-grade high-yield corporate bond, a separate credit-market category. Treasury's glossary, SEC explanation of high-yield corporate bonds
How the uniform-price auction reaches that yield
Treasury first awards eligible noncompetitive bids under its auction rules. It then fills the remaining offering with competitive bids, starting at the lowest yields and moving upward. If bids at the cutoff exceed the amount still available, Treasury awards only a proportion of those bids.
All successful competitive and noncompetitive bidders receive the same auction price, corresponding to the highest successful yield. A bidder who submitted a lower yield does not pay a different auction price for that reason. How Treasury auctions work, 31 CFR 356.20
Here is a simplified hypothetical note auction with $10 billion available, no noncompetitive bids and no SOMA add-on. Each row aggregates bids at that yield; it does not represent one investor.
| Submitted yield | Amount tendered | Amount awarded |
|---|---|---|
| 4.460% | $3 billion | $3 billion |
| 4.480% | $4 billion | $4 billion |
| 4.500% | $5 billion | $3 billion |
| 4.520% | $8 billion | $0 |
| Total | $20 billion | $10 billion |
The cutoff is 4.500%. Bids at that yield receive 60% of their requested amount because only $3 billion remains for $5 billion of bids. Every successful bidder gets the price corresponding to 4.500%, including those who bid 4.460% or 4.480%. Coverage is 2.00: $20 billion divided by $10 billion.
The example separates three things that are easy to mix up: the yields submitted, the amounts awarded and the common price paid.
High Yield, coupon and Allotted at High are different fields
In the actual May 28, 2024 note result, High Yield was 4.917%, the coupon interest rate was 4.875%, and the price was 99.920920 per $100 of face value. The reported 78.98% Allotted at High concerns the proportion awarded to bids at the cutoff, not the percentage of the whole auction bought by one group. Official note result
The coupon sets interest payments against face value; the auction yield also reflects the purchase price and payment schedule. For the broader bond concepts, see coupon rate, current yield and yield to maturity.
Bills use High Rate; TIPS and FRNs need their own labels
Check the security type before comparing numbers:
| Security | Auction field to read | Important distinction |
|---|---|---|
| Nominal Treasury notes and bonds | High Yield | The clearing yield, distinct from the coupon |
| Treasury bills | High Rate | The highest successful discount rate; Investment Rate is a separate yield measure |
| Treasury Inflation-Protected Securities, or TIPS | High Yield | A real yield, rather than a nominal note yield |
| Floating Rate Notes, or FRNs | High Discount Margin | A margin measure, rather than a fixed note's yield |
These distinctions follow Treasury's glossary and its auction-award rules.
For example, the August 1, 2024 28-day bill auction reported a 5.285% High Rate and a 5.381% Investment Rate. The latter was labelled an equivalent coupon-issue yield. These are different conventions applied to the same bill result, not two separate auction outcomes. Official bill result
Does a high bid-to-cover ratio mean a strong auction?
It indicates more tendered volume per unit accepted, but “strong” needs a comparison. Use a clearly identified set of previous auctions of the same security type and term. Check whether you are comparing a new issue with a reopening and whether offering sizes differ.
There is no universal pass mark that turns every ratio above 2.00 into good news. Even with unchanged bidding volume, a smaller denominator produces a higher ratio. The ratio also cannot tell you how many unique investors participated: that information is absent from an amount-based fraction.
Most importantly, bidding volume and the price investors require are separate dimensions. An auction can attract substantial bids while clearing at a higher yield than the market expected. Calling that a contradiction confuses coverage with pricing.
A tail needs a when-issued comparison
For a nominal note or bond, the usual yield comparison is:
Auction difference in basis points = (High Yield − when-issued yield at auction close) × 100, when both yields are written as percentage numbers.
The when-issued quote refers to trading in that security before issuance. Record the same security, the quote source, its timestamp and its quote convention. The New York Fed describes the usual comparator as the when-issued bid-side yield at auction close. A morning quote or yesterday's generic two-year yield is not interchangeable with it. New York Fed auction terminology
Consider a separate hypothetical example, unrelated to the historical auction above:
- When-issued bid-side yield at auction close: 4.500%.
- Auction High Yield: 4.520%.
- Difference: 0.020 percentage points, or 2 basis points.
The auction tailed by 2 basis points under that comparison. A clearing yield below the comparator is described as stopping through; an equal yield shows no difference from that quote. If you need a refresher on the units, see basis points versus percentage points.
You cannot calculate a tail from bid-to-cover, nor by subtracting Median Yield from High Yield. The median describes the distribution of accepted competitive tenders inside the auction. It is not an outside market expectation. Without a suitably timed when-issued quote, leave the tail unclassified.
Bidder categories add context, not an investor census
Treasury's result footnotes distinguish:
- Primary dealers: dealer submitters bidding for their own accounts.
- Direct bidders: non-primary-dealer submitters bidding for their own accounts.
- Indirect bidders: customers whose competitive bids go through a direct submitter. This category includes certain foreign official bids, but it is not synonymous with all foreign demand.
These are categories for submitting competitive bids. They do not, by themselves, identify every ultimate holder or explain each buyer's motive. If you calculate a category's share, say whether the denominator is competitive awards or a broader total. Those percentages answer different questions. Bidder definitions in Treasury's result footnotes
What can you conclude from the result?
Keep three conclusions separate:
- Coverage: the amount tendered relative to the relevant amount accepted.
- Clearing terms: the yield or rate and corresponding auction price.
- Surprise: how those terms compare with a defined pre-auction benchmark.
A high ratio does not guarantee that bond prices will rise or yields will fall afterward. It is one observation from one auction, not a forecast of every market participant's next decision. The same distinction between a reported number and its expectation helps explain why markets can react differently to the same news.
To read an auction yourself, open TreasuryDirect's auction results or historical auction search, then:
- Match the date, CUSIP, security type and term.
- Read the ratio footnote and reconcile its numerator and denominator.
- Identify the correct High Yield, High Rate or High Discount Margin field.
- Compare like-for-like auction history and bidder-category amounts.
- Add a tail or stop-through label only if you have the required when-issued quote.
That gives you a defensible description of the auction without turning a headline statistic into a trading recommendation.
Keep learning
Explore educational guides. These links do not open trading markets.
Sources
- U.S. Treasury, two-year note auction result, May 28, 2024.
- TreasuryDirect, Glossary for Treasury Marketable Securities and How Auctions Work.
- 31 CFR 356.20: Determining auction awards.
- Federal Reserve Bank of New York, Treasury rollover FAQs.
- U.S. Treasury, 28-day bill auction result, August 1, 2024.
- New York Fed researchers, FRN Follow-Up: Who Are the Market Participants?, January 14, 2015.
- U.S. Securities and Exchange Commission, High-yield Corporate Bonds.
This guide is educational and does not recommend a trade. The dated auction results are examples, not current market quotes.
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