日本国债为何被抛售？

Core Viewpoint - Japan's long-term government bonds are facing significant sell-offs, with the 30-year bond yield reaching a historical high of 3.22% as of August 27, driven by unexpected GDP growth and potential interest rate hikes by the Bank of Japan [1] Group 1: Market Dynamics - The rise in bond yields is attributed to a structural supply-demand imbalance in the Japanese government bond market, where the main buyers are pension funds, life insurance companies, and foreign investors [1] - The Bank of Japan, which has been the largest buyer of government bonds since 2013, plans to reduce its bond purchases starting March 2024, leading to a lack of buyers in the market [1][2] - In July, Japanese pension funds and insurance companies net sold 130 billion yen of bonds, indicating their inability to increase purchases due to asset allocation and capital regulation constraints [2] Group 2: Auction Results and Investor Sentiment - The bidding rate for the 20-year government bond auction in May was only 2.50 times, the lowest since 2012, prompting the Japanese government to reassess its bond issuance plans [3] - The government plans to issue 176.9 trillion yen in bonds this fiscal year, but has reduced the issuance of long-term bonds by over 3 trillion yen due to market conditions [3] - Investor concerns about Japan's political situation are evident, as the ruling party does not hold a majority in the Diet, complicating governance and potentially leading to further fiscal expansion [3] Group 3: Policy Challenges - The Japanese Ministry of Finance faces challenges in effectively managing the bond issuance strategy, as further reductions in long-term bond issuance would necessitate increased short-term bond issuance, leading to higher interest payments [4] - The Bank of Japan is unlikely to change its policy of reducing bond purchases due to its significant holdings of 575.9 trillion yen in government bonds and a book loss of 28.6 trillion yen [5] - Despite speculation about potential interest rate hikes due to external pressures, the current economic conditions and anticipated impacts from U.S. tariff policies make such a move unlikely [5]