Japan spent a record ¥15.4 trillion in one month to buy the yen

Japan spent ¥15.3993 trillion, about $96.5 billion, buying yen and selling dollars between 30 July and 26 August, the Finance Ministry said on Friday. It is the largest sum the ministry has recorded for a single intervention window. The previous mark was ¥11.7349 trillion during the Golden Week operations in late April and early May.

This year's combined intervention has now passed ¥27 trillion. That figure already exceeds the previous annual record of about ¥15 trillion set in 2024. A detailed day-by-day breakdown will not appear until quarterly accounts, expected in early November.

How the July round started

The dollar traded near ¥164 in late July, the weakest yen in about 39 years and eight months. A government source later confirmed that authorities entered the market on 30 July after the rate printed 163.99 on 23 July. Bank of Japan data published earlier this month suggest that single day may have absorbed as much as ¥9.6 trillion, which would beat the confirmed daily record of ¥6.3 trillion from 30 April.

On 31 July, Tokyo and Washington conducted a joint yen-buying, dollar-selling operation in New York hours. Finance Minister Satsuki Katayama and U.S. Treasury Secretary Scott Bessent confirmed the move on 3 August and called it the first coordinated intervention of that kind in about 28 years. Kyodo put the gap since the last joint action at 15 years. South Korean officials said the Bank of Korea timed its own won-buying to overlap, to increase the effect.

The yen jumped from around 163 per dollar toward 155.20 by 3 August. By 10 August it had settled near 159.50 and has stayed in that area. The ministry's Friday total covers the whole window through 26 August, so some of the cash was spent after the first bounce, defending the new range rather than creating it.

Why the yen keeps slipping

Traders have sold the yen on the gap between U.S. and Japanese yields and on doubt about Japan's fiscal path. Prime Minister Sanae Takaichi has promised heavy spending without a matching plan to pay for it. That mix keeps the currency under pressure even after a record official bid.

Intervention can change a rate for days or weeks. It does not, by itself, close a yield gap or a budget argument. Officials know this. The point of publishing a ¥15.4 trillion print is to show capacity. Washington has said Tokyo could draw on a COVID-era Federal Reserve backstop for major central banks if it needed to prove that capacity again.

Market desks had guessed the July-August window at ¥11 trillion to ¥12 trillion. The official number landed several trillion higher. That miss is useful. It means private estimates of how much firepower Tokyo used in a given week are still blunt, and that the ministry is willing to surprise on size.

What the number does not settle

A monthly record is a political fact as much as a market one. It tells households that the state spent a sum larger than many annual budgets to slow a slide they feel at the import counter. It tells funds that the official bid is real and large. It does not tell either group where the yen will trade in November, when the daily ledger appears and the next U.S. rate decision is closer.

Two rounds in one calendar year, totalling about $170 billion on Nikkei's arithmetic, also raise a separate question inside Japan: how much of the foreign-reserve stock the ministry is prepared to recycle into yen support if the dollar runs again. Reserves are large. They are not infinite at this burn rate.

Katayama and Bessent said they would not hesitate to coordinate again. That sentence is now backed by a line in the ministry's accounts. The market will test it the next time the dollar pushes through 160.