Treasury Doubles Long-Term Bond Buyback Cap to $4 Billion Starting September 9

The Treasury will double its per-operation cap on buybacks of nominal coupons with remaining maturities over 15 years from $2 billion to at least $4 billion, effective September 9, 2026 (release sb0607). The program, launched in 2024 to manage the outstanding debt portfolio, previously operated under a cap that trading desks viewed as modest relative to the stock of long-dated issues. The "at least" language preserves optionality to exceed the new floor. The expansion lands within the quarter-end positioning window, requiring portfolio managers to reprice on-the-run premia and cheapest-to-deliver bases in the 20-year and 30-year sectors. Primary dealers stand to see improved balance sheet capacity if buybacks absorb a larger share of less liquid off-the-run positions.