When-Issued Trading

A new Treasury note is announced days before it is auctioned, and auctioned days before it actually settles — yet dealers start trading it, quoting two-sided prices, almost as soon as the announcement hits. They are trading a bond that has no CUSIP transactions history, no coupon fixed in stone until the auction, and no legal existence yet. This is when-issued (WI) trading, and it is how the market prices a bond before the auction sets its terms.

How it works

Once the Treasury announces an auction — size, maturity, auction date — dealers begin quoting the new security on a yield basis (since the coupon isn't set yet) for settlement on the actual issue date. A buyer and seller agree today to exchange the bond on settlement day at a yield, with no cash changing hands until then. This is functionally a forward contract on a bond that hasn't been sold yet.

The auction itself then clears at whatever yield the bidding determines. If the WI market was trading the note at 4.05% right before the auction and the auction stops out at 4.06%, that one basis point gap is the "tail" — a small, closely watched sign of how accurately the WI market anticipated demand.

Worked example

A new 10-year note is announced Wednesday for auction the following Wednesday, settling the Thursday after. On Friday, a dealer sells $10 million WI 10-year notes to a client at a yield of 4.20% for settlement on the eventual issue date — no coupon is quoted because none exists yet.

1. The auction clears the following Wednesday at a high yield of 4.18% — lower than the 4.20% WI level, meaning demand was stronger than the market had priced in.
2. The dealer sold to the client at 4.20% (a lower price than where the bond ended up trading). Since yields fell, the bond's price rose, so the client who bought WI at 4.20% comes out ahead — they locked in before the market rallied into the auction.
3. Had the auction instead tailed — clearing at 4.24%, worse than the 4.20% WI level — the client's WI purchase would look poor by comparison, since they paid up for a bond the auction later showed was worth less.

WI trading therefore transfers auction-outcome risk onto whoever took the wrong side before the result was known, which is exactly why dealers use it to test demand and hedge inventory ahead of an auction.

What this means in practice

Primary dealers rely on the WI market to gauge how an auction will go before committing capital: heavy WI buying interest signals the auction will likely tail through (clear at a lower yield than expected), while thin interest warns of a weak auction. Portfolio managers use WI trades to lock in exposure to a new issue without waiting for settlement, and the WI yield published just before auction time is the standard benchmark against which auction results are judged "strong" or "weak."