U.S. and Japan Jointly Intervene in Yen Market for First Time in Nearly 30 Years
Miles Bennett
The US and Japan on July 31 jointly bought yen in direct market intervention — the first coordinated move in nearly 30 years. Tokyo's solo operation the day before was estimated at $52.8 billion, but with the rate gap still wide, staying power is in doubt.
What exactly did the two governments do?
The New York Fed, acting for the US Treasury, sold euros and bought yen while Japan's government and central bank did the same — the first joint US-Japan yen intervention since the late 1990s.
This means → Washington moved from verbal concern to real money on the table, a signal far stronger than Japan acting alone.
Treasury Secretary Scott Bessent had publicly called the yen "significantly undervalued" and said its "excessive volatility" was harmful — this action matches those words.
How big was the intervention?
Japan moved first on Thursday, buying yen on a massive scale. Bloomberg estimates the single-day operation at roughly ¥8.45 trillion (about $52.8 billion) — potentially Tokyo's largest-ever one-day intervention.
The yen surged as much as 3.3% that day; FX trading volume hit a 12-year high (CME data).
On Friday in New York, the yen rose another ~1.3% against the dollar, closing near 157.28; it also gained over 1% against the euro.
Why had the yen fallen far enough to need intervention?
The yen had slid to its weakest level since 1986, squeezed by three forces at once: rising oil prices lifting import costs, Japan's persistent fiscal deficit, and the widening interest-rate gap between Japan and the US.
In plain terms = US rates are high, Japanese rates are low, so money naturally flows from yen into dollars — that's what dragged the exchange rate down.
What did the Bank of Japan itself say?
The BOJ on Friday held rates steady, as most economists expected. Governor Kazuo Ueda said a hike was "possible at future meetings" but gave no clear signal.
This means → the central bank lists the weak yen as an inflation risk yet refuses to use interest rates to actively support it — intervention was funded by the Finance Ministry, with no policy backup from the BOJ.
Evercore ISI strategists Marco Casiraghi and Gang Lyu wrote: "Without narrower rate differentials, FX intervention is likely to be relatively short-lived."
Are traders still betting against the yen?
CFTC data show hedge funds held 124,575 short yen contracts as of July 28, with a notional value of roughly $9.5 billion — near the largest short position since 2007, set in June.
In plain terms = the pile of bets that the yen will keep falling is still near a historic peak. Intervention scared off some traders, but the big directional wager hasn't been unwound.
TD Securities economist Alex Loo said traders "may stay wary of further intervention," but the sheer size of the short overhang means the intervention's impact faces sustained pressure.
How long can the intervention hold?
Goldman Sachs analysts Michael Cahill and Lexi Kanter argued that intervention is not a "sustainable solution" but can still work in the short run — and Japan has enough FX reserves to keep it up for a while.
Rabobank FX strategy head Jane Foley flagged the key question: whether USD/JPY can stabilize near 160 without pushing higher.
This reflects the market's core tension: intervention can curb short-term speculation, but until the rate gap narrows, capital flows won't reverse — whether the yen holds its gains ultimately depends on when the BOJ actually raises rates.
Content is for reference only, not financial advice.