The Japanese yen weakened against the US dollar following the Bank of Japan's (BOJ) decision to maintain its current monetary policy without raising interest rates. The BOJ cited heightened economic uncertainty, including concerns over US tariffs and a downgraded growth outlook, as reasons for its cautious stance on additional rate hikes. As a result, the yen fell from around 143 yen per dollar to levels exceeding 145 yen per dollar, marking a three-week low. The widening interest rate differential between the US and Japan contributed to the yen's decline. Concurrently, Tokyo stock prices rose, with gains exceeding 500 yen at one point, driven by a weaker yen that benefited export-related companies. Market sentiment was influenced by optimism over US trade deals, which bolstered the US dollar. The BOJ governor highlighted economic uncertainties that tempered expectations for near-term monetary tightening, reinforcing the central bank's hold on policy.