A weak Japanese yen can make a trip to Japan feel like it came with a discount code. A ¥10,000 dinner costs about $91 at ¥110 per dollar, or $62.50 at ¥160 per dollar. Same sushi. Maybe one more plate. So why is the Japanese yen weak? One major reason is the gap between U.S. and Japanese interest rates. When U.S. investments pay more, investors have a reason to sell yen and buy dollars. For travelers, that can mean cheaper sushi. For Japanese households, a weaker yen can make imported fuel and food more expensive. And on July 31, 2026, U.S. Eastern time, Japan bought yen in coordination with the U.S. Treasury. Why would Washington get involved in the price of someone else’s currency? The answer starts with interest rates and ends up in the U.S. bond market. Japan’s Ministry of Finance Why higher U.S. interest rates can weaken the yen An interest rate is the price of borrowing money. If you lend a friend $1,000 and they pay you back $1,010 a year later, you’ve earn...