---
title: Bid-to-Cover Ratio
description: Bid-to-cover ratio explained: how the demand gauge in Treasury auctions is calculated, what counts as strong, and a worked example with real numbers.
source: Helious
canonical: https://helious.io/learn/bid-to-cover-ratio
---

# Bid-to-Cover Ratio

The **bid-to-cover ratio** is the total dollar value of bids submitted in a Treasury auction divided by the amount actually sold. It is the fastest single read on demand: a ratio of 2.5 means investors bid for two and a half times the paper on offer.

Traders watch it because it summarizes appetite for duration at the current yield level. A ratio well above the recent average for that tenor signals strong sponsorship and often coincides with a stop-through; a weak ratio suggests dealers had to absorb unwanted supply and frequently accompanies a tail.

- Rough desk baselines: 10-year notes tend to cover around 2.4–2.6x, 4-week bills often above 2.8x.
- Levels only matter relative to that maturity’s own history: comparing a bill cover to a bond cover is meaningless.

**Worked example:** Treasury offers $42 billion of 10-year notes and receives $107.1 billion in bids. Bid-to-cover is 107.1 / 42 = 2.55x. If the trailing six-auction average is 2.48x, that is a modestly strong result, and if the auction also stops 1.2 basis points through the when-issued yield, the market reads it as clean, genuine demand rather than dealers reluctantly warehousing supply.

## Questions

### What is a good bid-to-cover ratio?

There is no single number: it depends on the tenor. A 2.5 is strong for a 30-year bond and unremarkable for a 4-week bill, so the only reading that means anything is against that tenor's own recent history. Helious publishes every auction's cover next to the tenor's trailing twelve-auction average on [the auctions board](https://helious.io/auctions), so the comparison is already made for you.

### What does bid-to-cover actually measure?

Total bids divided by the amount the Treasury sold. A 2.5 means $2.50 was bid for every $1 issued. It measures the DEPTH of demand, not its quality, which is why it is read alongside the tail and the bidder split rather than on its own.

### Is a falling bid-to-cover a warning sign?

Only when it persists and shows up with a tail. One soft cover is noise; several in a row on the same tenor, with the stop clearing above the when-issued yield, is the market asking for a concession to absorb supply. Helious tracks the twelve-auction average per tenor and ranks each result against the full captured history.

## Live data

Helious measures this and publishes the current figures at [https://helious.io/learn/bid-to-cover-ratio](https://helious.io/learn/bid-to-cover-ratio), and through the get_auctions and get_rates_and_curve tools on its MCP server at https://helious.io/mcp.