On January 21, the Japanese government bond market experienced a massive sell-off, with the 30-year and 40-year yields rising by over 25 basis points in a single day. The 40-year yield reached 4%, hitting a new high since 2007. Concerns about fiscal sustainability arose after the Prime Minister proposed tax cuts and increased spending plans. The Nikkei 225 index fell by 718.60 points, and the Korea KOSPI index also declined, while U.S. Treasury yields rose.