US Treasury is increasing the size of nominal long-end; by at least double the size of liquidity support buyback operations for longer-dated nominal coupon securities, from the current USD 2bln to at least USD 4bln. As of September 9th.

Liquidity support buybacks are a relatively young part of the Treasury toolkit, and each step up in size has so far been absorbed without disruption, with operations in longer-dated nominal coupons drawing consistently heavy offer volume from dealers holding off-the-run inventory. Doubling the purchase size expands the bid for seasoned long-end paper, which in past operations of this kind has compressed the yield spread between off-the-run and on-the-run coupons in the targeted maturities and marginally improved market depth there; it is a technical, not a duration, signal, since buybacks are funded through issuance elsewhere rather than through net borrowing changes. The stated rationale, strong sponsorship and high-quality offers, matches the pattern of prior increases, where Treasury has scaled the programme incrementally rather than committing to a terminal size. The distinction worth drawing is between liquidity support buybacks, which are regular and targeted, and cash management buybacks, which are episodic and funded by surplus cash; this is the former, so the cadence is predictable. The follow-ons are the updated operation schedule, any shift in the maturity buckets targeted, and the next Quarterly Refunding, where Treasury has flagged further detail on sizing and where the composition of new issuance across the curve matters more for the long end than the buyback itself.