An unexpected expansion of the U.S. Treasury Department’s long-dated bond buyback program sent Treasury yields lower and pushed the US Dollar Index below 99, accelerating a broad rally in Asian currencies. The index last traded at 98.763, down 0.13% after two consecutive 0.89% declines, while its August 20 low of 98.557 was the weakest level since May 14 and marked a more than three-month low. The Korean won rose about 1% intraday and broke an 11-month high, leading gains that also lifted the yuan, Taiwan dollar and Japanese yen. On Friday, the People’s Bank of China (China’s central bank) set the yuan’s central parity rate 0.01% weaker at 6.7817, but onshore yuan rose 0.02% to 6.7235 after reaching 6.7219, its highest level since early February 2023. Offshore yuan gained 0.03% to 6.7233 after touching 6.7201 the previous day, a more than 42-month high. The onshore yuan is up about 3.93% this year and the offshore yuan 3.75%, making the domestic currency the strongest-performing currency in Asia. Traders said selling pressure near 6.72 could limit further near-term gains unless exporter settlement or foreign capital inflows strengthen. Markets are also watching whether the central bank uses the fixing or liquidity operations to slow appreciation as the exchange rate approaches 6.70. The Taiwan dollar also strengthened, although foreign-investor flows and possible central-bank intervention remain important variables. Investors viewed the Treasury buyback expansion as a short-term support for bonds that does not resolve the underlying U.S. debt-supply and fiscal-deficit concerns, potentially leaving the dollar vulnerable to further adjustment while raising the prospect of additional Asian currency gains.