Japan just set a new record nobody in Tokyo’s finance ministry wanted to break. The government spent 15.4 trillion yen on foreign exchange intervention last month, the largest single-month currency defense operation in the country’s history.
To put that in perspective, that’s roughly $100 billion deployed in a matter of weeks to buy yen and slow its slide against the dollar.
A mounting pattern of escalation
This new record eclipses what was already a year of extraordinary intervention. In 2024, Japan spent approximately 15.3 trillion yen (around $99 billion) across the entire year to stabilize its currency. The fact that a single month now matches a full year’s prior spending tells you everything about the trajectory here.
The previous monthly record was set during late April to May 2024, when Japan deployed 9.8 trillion yen.
Earlier this year, Japan conducted what was reportedly its largest single-day yen-buying operation on April 30, spending 6.28 trillion yen in a single session. Between late April and late May, the Ministry of Finance spent 11.73 trillion yen ($73 billion) on interventions.
The foreign reserves problem
Currency intervention isn’t free money conjured from thin air. Japan funds these operations by selling foreign assets, primarily US Treasuries and other foreign securities, to raise the dollars it then sells for yen.
That drawdown is starting to show. Japan’s foreign reserves dropped by approximately $77 billion in May alone, largely driven by the liquidation of foreign securities.
One notable development: Japan and the US conducted their first coordinated currency intervention since 1998 during July and August of this year.
Why the interventions keep failing to stick
Each round of yen-buying provides a temporary bounce, then the fundamental forces reassert themselves. The interest rate gap between US and Japanese government bonds makes holding dollars far more attractive than holding yen for yield-seeking investors. Geopolitical tensions, particularly in the Middle East, have also increased demand for dollars as a safe haven, adding further downward pressure on the yen.
Japan’s Ministry of Finance has historically focused its interventions on slowing the pace of depreciation rather than establishing a fixed exchange rate. The goal is damage mitigation, specifically limiting the impact on import costs. Japan imports the vast majority of its energy and a significant share of its food, so a weaker yen directly translates to higher prices for everyday goods.
Analysts have consistently pointed out that sustainable yen stabilization likely requires the Bank of Japan to raise interest rates more aggressively. Higher Japanese rates would narrow the differential with the US, reducing the incentive for capital to flow out of yen-denominated assets. But the BOJ has moved cautiously on rate hikes, wary of choking off an economy that spent decades fighting deflation.
Japan remains the largest foreign holder of US Treasury securities. Sustained selling of those holdings to fund yen interventions could, at scale, put upward pressure on US bond yields.