Yen jumps to one-month high as traders weigh chance of further intervention

The rate of the yen against the US dollar displayed in the trading room at foreign exchange brokerage Gaitame.Com Co. in Tokyo, Japan, on Thursday, Sept. 3, 2026. Source: Bloomberg | Bloomberg | Getty Images

The Japanese yen strengthened sharply on Thursday, reaching a one-month high against the U.S. dollar, as traders weighed the possibility of further intervention by Japanese authorities alongside rising expectations for Bank of Japan (BOJ) rate hikes.

Key Market Movements

• The yen jumped more than 1% against the greenback, briefly touching 156.34 per dollar — its strongest level since August 3, according to LSEG data.
• At 4:20 a.m. ET, the yen was trading at 157.1 per dollar.
• The yen also gained ground against the euro and the British pound.

Intervention Speculation

The currency move follows a similar sharp 1% spike on Wednesday, which fueled speculation among market watchers about whether Japanese authorities had staged another round of action. Earlier this week, the yen crossed the 160-per-dollar mark, a key threshold that typically increases the likelihood of intervention.

Japan spent a record 15.4 trillion yen ($98 billion) to boost the yen between July 30 and August 26, according to its finance ministry. The U.S. separately confirmed its participation in a coordinated effort in late July, using its foreign-currency holdings to buy yen. Washington has not disclosed the exact amount, though a July 31 Reuters photo showed U.S. Treasury Secretary Scott Bessent's notepad reading: "Buy Japanese Yen (JPY) $5-10 bil."

Official Commentary

Bessent told CNBC on Monday that he believed the Japanese government and BOJ would take action leading to a stronger yen. He also privately urged officials to communicate the path of interest rates, according to local media.

Officials in both Washington and Tokyo have expressed concerns that disorderly moves in the yen could destabilize global markets.

Analyst Views

Takuji Okubo, chief economist at Japan Macro Advisors, told CNBC it is "possible" Thursday's move represented further Japanese intervention. However, he noted: "I do not think [the Ministry of Finance] has done this kind of small stealth intervention in recent history. So it is probably just a..."

Market watchers suggested the move was more likely tied to raised bets on a BOJ rate hike this month, following hawkish comments from policymakers. The central bank's next policy decision is due September 18.

Bond Market Context

Japanese government bond yields eased following a solid sale of 30-year dated debt, after coming under pressure amid a global sell-off and investor concerns about the country's fiscal position as it finalizes its 2027 budget.

Broader Implications

Analysts warn that prolonged weakness in the yen could prompt domestic investors to reduce their holdings of U.S. Treasurys. Japanese investors are by far the largest overseas holders of Treasurys, with approximately $1.1 trillion worth of U.S. debt on their books as of June, according to the Department of the Treasury.

Related: Japanese borrowing costs hit 30-year high as Bessent says Tokyo may intervene to boost yen