How fast does the auction panel update after results?
Seconds. Helious captures the Treasury results as they cross and scores the tail, cover and bidder split immediately, rather than waiting on a wire desk to write a recap.
Auction Analysis: Reading the Tail, Stop-Through, Verdict and Bidder Split
The auction panel scores every US Treasury auction the moment results cross the tape, no waiting on a wire desk to write it up. It carries four things a rates trader actually reads: the tail (or stop-through) in basis points, the bid-to-cover against its own trailing average, the indirect/direct/dealer split, and a one-word verdict. This page explains each field and how to read them together. For the underlying concepts in prose, the step-by-step how-to-read-a-treasury-auction guide walks a live worked example.
The tail (or stop-through)
The headline number is the auction tail: the auction's high (stop-out) yield minus the when-issued yield trading in the seconds before the bid deadline. Helious sources the real when-issued level, not a reconstructed proxy, so the print is honest. A positive number means the auction tailed. It had to concede yield to clear, a soft result. A negative number is a stop-through: demand cleared richer than the screen, a strong result. Both sides are shown in basis points so a 1.8bp tail and a 0.6bp stop-through read at a glance. Coupons tail; bills carry no tail (discount vs investment-rate basis), so the front end is read on cover and the bidder mix instead.
Bid-to-cover vs the 12-month average
Bid-to-cover is total bids divided by the amount sold: demand depth. The absolute number means nothing across tenors, so the panel always pairs it with the tenor's own 12-month average. A 2.35 cover is soft for a 10-year note but strong for a 30-year bond; the panel does that comparison for you. A cover fading below its average over successive auctions is the classic tell of waning demand, which is why the average travels next to the print.
The bidder split
The three takedown shares: indirect, direct and primary-dealer, split 100% of the competitive award. High indirects (largely foreign central banks and real-money bidding through dealers) plus a low dealer take means genuine end-investor demand absorbed the supply. A swollen dealer take is the opposite: the street was left holding what investors passed on. The split often tells you more than the tail alone, especially when the two disagree.
The verdict
Helious rolls the tail, the cover-vs-average and the bidder split into a single STRONG / IN LINE / WEAK verdict so you can triage in one glance and dig into the fields only when it matters. A stop-through with above-average cover and heavy indirects prints STRONG (supportive for the curve); a tail with a soft cover and a fat dealer take prints WEAK (a concession that can lift yields). Track a tenor's history on the auction hubs, watch the running numbers in the tail dataset, or catch the next one score live on the [desk](/).
FAQ
Is the when-issued tail real or reconstructed?
Real. The panel computes the tail against the actual when-issued yield trading just before the bid deadline, not a proxy backed out of other prints, so a small coupon tail or stop-through is trustworthy.
Why does a bill auction show no tail?
Bills are quoted on a discount-rate basis while the when-issued market trades on an investment-rate basis, so a like-for-like tail isn't meaningful. Read bills on bid-to-cover and the indirect/direct/dealer split instead.
Where can I see an auction's history over time?
Each tenor has its own hub, for example the 10-year note, and the full running series lives in the Treasury auction tails dataset.