South Korean treasury bond yields rose across all maturities on the 21st as long-term U.S. Treasury yields climbed again and the government unveiled plans for a future response fund. The three-year yield rose 0.043 percentage point to 3.854%, the five-year yield increased 0.045 percentage point to 4.111%, and the 10-year yield gained 0.053 percentage point to 4.376%. U.S. long-term yields, which had briefly declined after the U.S. Treasury announced an expansion of its bond buyback program, reversed within a day to around 4.7%, their level before the announcement. The 10-year sector also faced selling linked to auction options after market rates fell below the recent winning yield of 4.415%. The government will direct tax revenue above its long-term trend into a future response fund for young adults, growth engines, regional development, education and talent. Analysts said this approach could limit any reduction in bond issuance that might otherwise follow higher tax revenue, including revenue generated by a semiconductor boom.