《海外非美经济探究》系列第五篇：解构日元贬值与日股大涨之谜

Group 1: Currency Dynamics - The Japanese yen depreciated by 0.9% against the US dollar since 2026, while the Japanese stock market surged by 7.1%[1] - The depreciation of the yen cannot be solely explained by narrowing interest rate differentials, as it is influenced by three factors: weak sustainability of US-Japan interest rate differentials, imbalances in the international balance of payments, and uncertainties in Japan's economic recovery[2] - The yen's depreciation is exacerbated by structural trade imbalances and capital outflows, with net foreign investment in Japanese securities reaching -1.58 trillion yen as of December 2025[20] Group 2: Stock Market Drivers - The Nikkei 225 index rose by 26.2% in 2025 and 7.1% in early 2026, driven by high inflation, moderate economic recovery, and government fiscal policies[24] - Key factors supporting the stock market include high inflation leading to increased corporate profits, expectations of fiscal expansion under Prime Minister Kishida, and strong exports in the AI sector[3] - The fiscal budget for 2025 saw a 31.0% increase in supplementary budget and a 6.3% increase in the initial budget compared to the previous fiscal year, indicating a commitment to economic stimulus[10] Group 3: Future Outlook - The Japanese stock market is expected to maintain high levels in 2026, with potential boosts from rising consumer spending as inflation recedes and real income levels improve[4] - The yen may continue to face pressure in the first half of 2026, but there is potential for a reversal in the second half as the Federal Reserve enters a rate-cutting cycle, narrowing the interest rate differential[5] - The yield curve for Japanese government bonds is anticipated to exhibit a "bear steepening" trend in the first half and a "bear flattening" trend in the second half of 2026[6]