Treasury auction bid-to-cover (10y / 30y)
Ratio of total bids received to amount accepted at long-end Treasury auctions; trailing six-month average.
Reading
Where fiscal stress shows up at market speed. Watch the trend, not the individual print — single auctions are noisy.
Thresholds
- watch2.3 — below the post-2010 norm
- alarm2 — sustained weak demand at the long end
Context
Why this matters
Bid-to-cover at long-end Treasury auctions is the highest-frequency window onto whether the Treasury can continue to fund the deficit at current yields. The ratio is noisy auction-by-auction (a soft 10-year print today can be reversed by a strong 30-year tomorrow), so the trend matters more than the individual reading. A trailing six-month average below the post-2010 norm is the meaningful signal — it suggests the marginal foreign and primary-dealer bid is thinning, which historically has preceded yield-curve repricing.
Who watches this
- Jeffrey Gundlach (DoubleLine) — references bid-to-cover in his macro webcasts
- David Rosenberg (Rosenberg Research) — references rolling auction averages as a leading indicator in Rosenberg Research notes
- Lyn Alden — frames the bid-to-cover within the broader "who buys Treasuries" question
- Russell Napier (Library of Mistakes) — historical comparative on auction stress across cycles
- Mohamed El-Erian — translates auction moves into broader funding-market implications
Recent history
Bid-to-cover ratios have held in the post-2010 band on average, but the dispersion has widened. Specific auctions (long-end 2024–25) have printed weak; others have printed strong on rate-cut expectations. The trend is to monitor over a 6-month window, not within any single month.
What would change my read
A sustained sequence of weak prints (trailing six-month average below 2.3 on the 10-year) would signal genuine marginal-buyer fatigue. The reverse — bid-to-cover ratios rising into 3.0+ — would suggest the funding market is comfortably absorbing supply at the current yield band.