Japan reveals record ¥7.98 trillion one-day yen intervention, three days of buying in July and August

Japan spent a record ¥7.9756 trillion, roughly $50 billion, buying yen in a single day on 30 July 2026, according to daily intervention data released by the Ministry of Finance on Monday 9 November. The ministry also disclosed ¥5.5523 trillion of yen buying on 31 July, the day of a coordinated operation with the United States, and a further ¥1.8714 trillion on 3 August.

Together the three days add up to ¥15.3993 trillion, the largest amount Japan has spent supporting its currency in any month. The figures confirm the scale of the summer push to stop the yen's slide past 160 per dollar, but they also show its limits: in Tokyo trading on 9 November the dollar was around ¥158, according to Reuters.

What did the Finance Ministry publish?

The ministry publishes monthly intervention totals at the end of each month and a day-by-day breakdown each quarter. Its 9 November release for July to September lists three operations, all selling US dollars and buying Japanese yen:

• 30 July 2026: ¥7,975.6 billion
• 31 July 2026: ¥5,552.3 billion
• 3 August 2026: ¥1,871.4 billion

The total matches the record ¥15.3993 trillion monthly figure the ministry had already disclosed for the period from 30 July to 26 August. What is new is how it was split. Bloomberg, via The Japan Times, reported that the third day surprised traders, who had believed the action took place over two days. Tsuyoshi Ueno, senior economist at NLI Research Institute, told Reuters that an intervention of nearly ¥2 trillion on 3 August was "surprising".

Reuters also reported that the ministry's monthly figures for September and October were zero, meaning there has been no further intervention since August.

How does this compare with earlier interventions?

The 30 July operation beat the previous one-day record of ¥6.2787 trillion, set on 30 April 2026, according to Reuters, citing ministry data going back to 1991. The Asahi Shimbun reported that Japan had already spent ¥11.7349 trillion across 30 April and 4 and 6 May this year, before the summer round.

The 31 July action was historically unusual. Japan and the US confirmed they had jointly entered the market that day, the first coordinated operation to support the yen since June 1998, after the Asian financial crisis, and the first joint yen intervention of any kind since March 2011, when the G7 sold yen after the Great East Japan Earthquake. Reuters reported that the US side sold euros for yen. The US Treasury has not disclosed how much it spent, so Japan's figures cover only its own share.

Reuters also reported at the time that South Korean officials said the Bank of Korea timed its own won-buying intervention to coincide with Japan's.

Why was Japan intervening?

The yen had fallen to its weakest level in almost 40 years. The Asahi Shimbun put the low in the 163-yen range against the dollar in late July; Reuters described levels near 164. A weak currency raises the cost of imported energy and food for Japanese households and companies, even as it helps exporters.

In currency intervention, the Finance Ministry decides when to act and the Bank of Japan carries out the trades as its agent. To buy yen, Japan sells some of its large foreign-currency reserves, mostly dollars.

Ueno told Reuters the scale "underscored the government's sense of urgency" and that, at the time, the dollar looked set to test ¥165. He linked the yen's weakness partly to the situation around Iran, which he said has not been resolved, and to structural factors in Japan's economy, and said downward pressure on the yen could continue.