Yen exchange rates have surrendered most intervention-led gains, leaving September’s BoJ decision and guidance on further tightening as the crucial tests.

The US Dollar to Japanese Yen (USD/JPY) exchange rate ended e week at 158.98, within touching distance of the 160 level despite the exceptional intervention conducted jointly by Japan and the United States.

The operation briefly drove USD/JPY from above 164 to around 155, but much of that Yen recovery has since been reversed.

Intervention succeeded in breaking the earlier momentum, although it did not remove the wide US-Japan interest-rate gap or the inflationary pressure created by expensive energy and a weak currency.

Attention has consequently shifted towards the Bank of Japan’s September 17–18 policy meeting.

Natixis economists Alicia García Herrero and Kohei Iwahara expect the BoJ to raise its policy rate by 25 basis points to 1.25% on September 18.

They said the central bank is “set to raise the policy rate by 25-bps” as inflation pressure strengthens.

Japanese headline inflation accelerated from 1.6% to 1.9% in July, while the measure excluding fresh food and energy also rose to 1.9%.

The more immediate concern for policymakers is the scale of imported inflation.

Yen-denominated import prices climbed 29.1% over the year, while producer-price inflation held at 7.2%, increasing the risk that companies will pass further cost increases to consumers.

Natixis expects additional quarter-point rate rises in January and July 2027, which would take the policy rate to 1.75%.

Analysts Back a September Increase

MUFG’s Derek Halpenny also expects a 25-basis-point move next month.

He said the inflation figures “back up current market pricing, and our view, that the BoJ will hike rates by 25bps” in September.

Markets have already priced a high probability of an increase, which helps explain why the Yen gained relatively little after the latest inflation release.

A widely anticipated rate move will only provide lasting support if Governor Kazuo Ueda signals that further tightening can follow within a reasonably short period.

Standard Chartered has also brought its next expected increase forward from October to September and raised its terminal-rate forecast from 1.50% to 1.75%.

The bank nevertheless doubts that policymakers can exceed already hawkish expectations, stating: “We doubt the BoJ can ‘out-hawk’ the market.”

Standard Chartered forecasts USD/JPY at 158 at the end of the third quarter and 160 at year-end, suggesting that gradual rate increases will not automatically produce a sustained Yen recovery.

Near-Term USD/JPY Forecast: Intervention Risk Caps 160

OCBC strategists Sim Moh Siong and Christopher Wong also see a stronger policy commitment as essential.

They warned: “A more meaningful and sustained JPY recovery will likely require a stronger signal from the BoJ that policy normalisation can proceed at a faster pace.”

Our base case is for USD/JPY to trade between 156 and 160 ahead of the September meeting.

A rate increase accompanied by guidance towards another move in early 2027 could push the pair below 156 and expose the intervention low near 155.20.

A cautious hike presented as an isolated response to imported inflation would leave 160 vulnerable, with a break higher bringing 162 and the pre-intervention region around 164 back into view.

Failure to raise rates would create an even greater risk of renewed Yen selling and another intervention response.

BoJ Deputy Governor Ryozo Himino’s August 27 speech and Tokyo inflation data on August 28 will provide the next domestic policy signals.

US PCE inflation and Federal Reserve Chair Kevin Warsh’s Jackson Hole address will be equally important, since a durable Yen recovery still requires some narrowing of the US-Japan rate gap.