US long-dated Treasuries extended their decline on Thursday after the Treasury Department announced its latest buyback targets. The department tripled the notional size of its repurchase operation for 10- to 20-year notes to $6 billion, a move that fell short of the levels some strategists had previously anticipated. As a result, the 30-year Treasury yield climbed to its intraday high, advancing roughly 4 basis points on the day.

The yield curve steepened accordingly, with the 5s30s spread widening to approximately 69 basis points, marking its most pronounced level of the session. Long-end swap spreads had ticked higher ahead of the Treasury announcement but quickly retraced to near-flat levels once the $6 billion buyback figure was confirmed.