The Japanese yen just hit its weakest level against the dollar in 40 years.

Yen per US dollar, 1986 to 2026, against its 1986 level of about 160 (dashed). A higher line means a weaker yen: it strengthened to a record 80 in 2011, then fell all the way back to about 162, the weakest in 40 years.
- For years the Bank of Japan held interest rates near zero to fight deflation, while the US Fed raised its rate toward 4%, so money floods to where it earns more, out of yen and into dollars.
- Even after the BOJ finally lifted rates to 1%, a 30-year high, the gap with the US stayed wide, so the pressure on the yen barely eased.
- Japan imports most of its energy and food, so a weak yen makes those costlier at home even as it flatters exporters and draws record tourism.
A cheap yen is double-edged: a boon for Toyota and tourists, a tax on every Japanese household's groceries and fuel. And it is a global tripwire: the "carry trade" that borrows cheap yen to buy assets worldwide can unwind violently, as it did in 2024, jolting markets far from Tokyo.