Invoice Spread Trades

A swap spread trade — long a Treasury, receive fixed on a matched-maturity swap — is a bread-and-butter relative value position, but it needs financing on the cash bond leg, which means it's exposed to repo-rate risk over time. A trading desk that wants the same swap-spread exposure without the repo-rollover headache can instead trade the futures contract against the swap. That combination — long or short a Treasury futures contract against an offsetting swap position — is an invoice spread.

Why "invoice"

The name comes from the invoice price: the amount a short futures position must pay to deliver a bond into the contract, equal to the futures settlement price times the bond's conversion factor, plus accrued interest. The yield implied by that invoice price — essentially, the yield the cheapest-to-deliver (CTD) bond would need to have for the futures price to be fair — is what gets compared to the swap rate of matching maturity. Trading the futures contract against the swap is trading that implied yield against the swap-implied government-financing rate.

Worked example

The 10-year Treasury futures contract's CTD bond currently implies a yield of 4.22%. The matched-maturity 10-year swap rate is 4.05%. A desk that believes swap spreads (swap rate minus Treasury yield) will widen — say, because dealer balance sheets are shrinking and Treasury supply is heavy, pushing Treasury yields up relative to swaps — sells the futures contract (effectively going short the CTD-implied yield exposure, i.e., positioned for Treasury yields to underperform) and pays fixed on the swap. If the swap spread widens from -17bp (4.05% - 4.22%) to -25bp because Treasury yields cheapen further relative to swaps, the position profits from both legs moving in the anticipated direction, without ever needing to source or finance the actual CTD bond in repo.

Worked example: rolling the trade

Suppose a fund holds a 5-year invoice spread and the futures contract approaches expiry. Rather than take delivery of the underlying bond, the fund rolls the futures position into the next quarterly contract, paying or receiving the roll spread between the expiring and new contract. If the roll costs 1.5bp against the position, that cost has to be weighed against the swap-spread thesis: a trade expected to earn 8bp of convergence over the next two quarters can absorb a couple of 1.5bp rolls and still be profitable, but a thin-margin trade might not survive several rolls of adverse cost.

What this means in practice

Invoice spreads let macro and relative-value desks express swap-spread views with futures-market liquidity and margining instead of repo financing, which matters most when repo markets are volatile (quarter-ends, debt-ceiling episodes) and cash bond financing becomes unpredictable. The tradeoff is that the futures leg carries CTD risk: if the cheapest-to-deliver bond switches to a different issue with different duration or yield characteristics, the trade's sensitivity to swap spreads shifts underneath the trader without any new position being put on.