What moved
On 18 September the Bank of Japan raised its policy rate by a quarter point to 1.25 per cent, a 31-year high, on a 7–2 vote. It follows the Federal Reserve, which lifted to 3.75–4 per cent on Wednesday, its first increase since 2023, and the European Central Bank, up a quarter point to 2.5 per cent the week before. Three of the major funding currencies tightened inside a fortnight, each pointing to the same global inflation impulse. Japan’s ten-year now sits near 3 per cent, a thirty-year high.
Why it matters for pricing
A multi-currency intercompany book is usually assumed to hedge itself. Some currencies tighten, others ease, and the legs offset. That holds when central banks move on their own clocks. It does not hold in a fortnight when three of them move the same way, driven by one impulse rather than three local stories. The diversification was correlation waiting to surface. This month it surfaced, and every dollar, euro and yen facility that renews now reprices upward with no offsetting leg.
The move is also larger than the headline, in each currency at once. The Bank of Japan raised 25 basis points; the ten-year JGB is at a thirty-year high near 3 per cent, so the long end has travelled far further than the policy rate. Intercompany loans are termed, and priced off the medium and long curve, not the overnight rate. A fixed-rate loan set correctly in 2021 stays arm’s length to maturity — that rate risk was assumed at inception. The exposure is the renewal, priced against today’s curve, and the cash pool, which reprices continuously.
The third effect is structural. A decade of treasury design used the yen, and to a degree the euro, as the cheap funding leg: borrow where money is cheapest, on-lend up. That shaped where groups located intercompany debt, not only how they priced it. As the cheap leg reprices and the carry differential compresses, the rationale for those structures weakens — and an authority testing an intercompany yen loan will measure the arm’s length rate against today’s yen curve, not the cheap-yen world the structure was built in.
Our call. The co-movement is episodic, not permanent — the BoJ board is turning more dovish, and the Fed and ECB may pause. But while it lasts, cross-currency diversification gives you nothing. Expect renewal costs across dollar, euro and yen books to rise together over the next two quarters, ahead of the policy moves, and expect carry-funded structures to draw the first questions.
What this means for your business
- Stress the book for correlated moves, not independent ones. The scenario where dollar, euro and yen benchmarks rise together is the one a currency spread does not cover.
- Price renewals off today’s curve, not last year’s coupon. Fixed-rate loans running to term are unaffected; the exposure is at maturity, roll-forward and in the cash pool.
- Read the term, not the policy rate. A 25 basis point move can sit beneath a long-end move several times larger, and your loans price off the curve.
- Revisit any structure built on cheap yen or euro funding. If the rate or the location rationale rests on a funding cost that has just repriced, it will be tested against the new curve.
Sources
Bank of Japan, Statement on Monetary Policy, 18 September 2026 (policy rate and 7–2 vote). Federal Reserve, FOMC statement, 16 September 2026, and European Central Bank, monetary policy decisions, September 2026 (target ranges). Market levels — ten-year JGB, yen and Nikkei — and the common-driver framing (Middle East conflict, AI-boom investment) per Reuters and Financial Times reporting, 18 September 2026, attributed as such; no FT text or charts reproduced. Figures as at 18 September 2026.