US Treasury yields fell sharply after the Treasury announced it would significantly expand its purchases of long-dated government debt. The department said it would at least double the size of liquidity-support buyback operations covering securities with maturities from 10 to 30 years. The move came after 30-year Treasury yields recently climbed to their highest level since 2007, raising concerns about liquidity and market stability. Following the announcement, yields declined across the curve, with the 30-year rate falling as much as 9 basis points to 5.19%. The decision signals that Treasury officials are prepared to intervene if borrowing costs rise too sharply or market liquidity deteriorates. The announcement also came ahead of a $16 billion auction of new 20-year bonds, adding further focus to demand for longer-dated debt. Treasury Secretary Scott Bessent previously described the buyback program as an important tool for addressing market dislocations and supporting liquidity.