South Korean national bond yields increased on May 31st, driven by growing expectations of a US interest rate hike. The increase reflects market sensitivity to potential monetary policy changes in the United States. However, the rate of increase decelerated in the afternoon trading session, suggesting some stabilization. Investors are closely monitoring the Federal Reserve's next steps as rising US rates can impact global financial markets. This situation creates uncertainty for the South Korean economy, potentially affecting borrowing costs and investment. Further developments in US monetary policy will likely continue to influence the domestic bond market. The overall market reaction indicates caution and anticipation of further shifts.