The Bank of Japan raised its policy rate by 25 basis points to 1.25% on Friday — the highest Japanese rates have been in 31 years. Then everything that was supposed to follow didn't. The yen fell, with the dollar pushing past 157 yen. The Nikkei 225 rose about 1.4%. Ten-year JGB yields dropped to roughly 2.98%, a third straight session lower.

The textbook says a rate hike lifts the currency. Here's why this one did the opposite.

The hike was the least surprising part of the day

1.25% had been priced in for weeks — Nikkei Asia flagged it as effectively settled a week before the meeting. What traders were actually waiting on was the guidance, and Governor Kazuo Ueda's was deliberately non-committal: more time is needed to see whether price increases stay stable, with wage growth still to be watched. Two of the nine board members voted against hiking at all, citing doubts about the strength of growth (AP). A hike delivered with a "we're in no hurry" message is a dovish hike, and the yen carry trade — borrow cheap yen, buy higher-yielding assets abroad — has no reason to unwind while Japanese rates sit far below the Fed's and the ECB's 2.5%.

Who actually did the lifting

The index gain wasn't a vote on BOJ policy. Trading Economics reported the work was done by chip and AI-linked heavyweights: Lasertec +5.5%, SoftBank Group +4.1% and Advantest +4%. In a price-weighted index like the Nikkei those three punch well above their market caps, so most of the 1.4% is a Tokyo echo of Wall Street's chip rally — not a rates story at all. Worth noting these same semis were among Thursday's losers, so a chunk of this is a bounce.

The ripple worth tracking

A weaker yen is a straight earnings tailwind for exporters. Toyota books more yen for every car it sells in dollars, and because the cost base is already in yen, that translation gain falls close to unchanged down to operating profit. Banks get the other side of it — rising short rates widen lending margins. Importers and households wear the cost, since Japan buys its energy in dollars.

The one thing that flips this

The yen itself. The dollar traded above 160 yen earlier this year, and US Treasury Secretary Scott Bessent has publicly pressed the BOJ to move faster (Trading Economics). If the dollar breaks back through 160, intervention chatter and a faster hike path return immediately and the "dovish hike" read unwinds hard. That level, and Ueda's next set of remarks, are the concrete triggers — the full central-bank schedule is on the calendar, and the day's biggest moves are on movers.

As of 18 Sep 2026, 2:45 pm IST / 5:15 am ET. Sources: Al Jazeera, AP, Trading Economics, Euronews. For discussion and education only — not investment advice. Verify before acting.