The US government has never failed to sell its debt at auction, and it can’t. But a Treasury auction tail tells you when a sale went badly anyway. On Sept. 23, a $70 billion sale of five-year notes produced one of the biggest tails in years, and the bond market noticed.
Here’s why “failure” isn’t on the menu. A small group of large banks, called primary dealers, have agreed to bid at every Treasury auction. If ordinary buyers don’t show up, the dealers take what’s left. So the question is never “did it sell?” It’s “how hard did the government have to push?”
That’s what the tail measures. Before an auction, the new notes already trade in a pre-sale market called “when-issued.” That market sets an expected yield, which is the interest rate traders think the auction will land at. The tail is the gap between that expectation and the real result. Think of a used-car dealer who hears in the morning that a car will sell for $20,000, then has to knock a few hundred dollars off at closing time to get the deal done. For bonds, a higher yield means a lower price. So a tail means buyers asked for a discount nobody had planned for.
On Sept. 23, the five-year notes cleared at 5.033%, the highest auction yield for that maturity since 2006, Bloomberg reported. The pre-sale market had priced 5.002%. That’s a tail of 3.1 basis points (a basis point is one hundredth of a percentage point). The average over the previous six five-year auctions was 0.6.
Three other numbers show who stepped back. Total bids came to 2.21 times the amount on sale, the weakest ratio since late 2018. Indirect bidders, the group that includes foreign central banks, took 54.3% of the notes, well below their recent average of about 65%. And dealers were left holding 15.8%, roughly $11 billion of notes that other buyers passed on.
The indirect number matters most. Foreign official buyers have long been a quiet backbone of this market. When they buy less, somebody else has to fill the gap, and I looked at who that might be in Marginal Buyer. It also ties back to why Japan used a repo facility instead of selling Treasuries to defend the yen. The biggest holders are working hard not to become sellers, even while they show up less at new auctions.
One weak auction can be noise, so the next day mattered. On Sept. 24, a $44 billion sale of seven-year notes tailed by 0.7 basis points against an average of 0.2, and indirect bidders again took well below their usual share. A smaller tail, but the same direction. That is the limit of a single Treasury auction tail: it can’t tell you if you’re looking at a bad day or the start of a pattern. Two in a row doesn’t settle it. It does shift the burden of proof.
Why should anyone outside a bond desk care? Because five- and seven-year yields feed into what lenders charge for car loans and business loans, and they move alongside the longer rates that shape mortgages. When the US government has to pay more to borrow, most people who borrow in dollars end up paying more too.
The next test comes fast. Treasury sells 10-year notes on Oct. 7, and August inflation data (the PCE report) lands on Sept. 30.
My take: An auction that can’t fail doesn’t break. It flinches.
Not advice. Just how I see it.