What Pushed the Yen to a 40-Year Low
The Japanese yen spent much of 2024 in freefall, sinking to its weakest point in roughly 40 years.
Several forces teamed up against it.
U.S. interest rates stayed far higher than Japan’s so investors naturally chased better returns in dollar assets.
This fueled the carry trade where people borrowed cheap yen and invested it elsewhere.
Think of it like borrowing lunch money at zero interest and investing it in something actually profitable.
Meanwhile Japan imports about 90% of its energy so rising oil costs drained money outward.
Structural problems like slow growth and massive public debt made everything worse. The US–Israel war with Iran and its associated oil shock added further upward pressure on U.S. inflation expectations, reinforcing the Fed’s resolve to hold or raise rates.
Escalating geopolitical risks worldwide also eroded the yen’s traditional role as a safe-haven currency, meaning it no longer reliably strengthened during periods of global turmoil.
Global investors’ response was amplified by changes in expectations about future policy via the interest rate channel, which helped push the yen lower.
Why the U.S. Chose to Get Involved
When a close ally is in trouble, sometimes you step in to help — and that is exactly what the United States did. America joined Japan’s currency rescue for several smart reasons. First, the U.S. wanted to protect its own bond market. Japan holds over $1.1 trillion in U.S. Treasury bonds. If Japan sold those to raise dollars alone, U.S. borrowing costs could spike. Second, a crashing yen threatened other Asian currencies too. Third, having two powerful governments act together sent markets a clear message: betting against the yen just got much more expensive. The inflation-adjusted yen had fallen back to low levels of the 1960s, making the case for intervention even more compelling. Coordinated action also reflected concerns about global financial stability, as central banks often intervene to calm markets during crises.
What Made This Yen Intervention So Unusual
By almost any measure, this yen intervention broke the mold. The last time the U.S. and Japan jointly bought yen together was 1998 — older than most smartphones. Central banks typically coordinate policy moves at meetings to influence exchange rates and markets, illustrating how central bank policy can have cross-border effects.
The last U.S.-Japan joint yen intervention was 1998 — a financial relic older than most smartphones.
Even stranger, the Treasury bought yen using euros instead of dollars. That almost never happens.
Analysts at HSBC called it “highly unusual — maybe unprecedented.” Barclays noted the euro choice kept things focused on the yen without hinting at broader dollar weakness.
On top of that, the Treasury quietly warned banks ahead of time it might act. Normally surprise is the whole point.
This operation rewrote nearly every rule in the playbook. Tokyo sold almost $59 billion of US dollars to buy yen when the intervention struck New York markets.
How the Two Governments Executed the Trade
Breaking those unusual rules required an unusual plan. Both governments coordinated carefully before markets opened. A speakerphone call inside Japan’s finance ministry gave the green light late on July 30.
Japan then jumped in directly buying yen and pushing its value from 162.80 to 157.80 per dollar almost instantly.
- Japan spent an estimated $36–85 billion buying yen
- The U.S. sold euros instead of dollars to buy yen
- The Federal Reserve Bank of New York handled the U.S. trades
- Goldman Sachs and Morgan Stanley were the executing banks
Together they sent speculators a loud warning. The coordinated intervention relied on direct market access and sophisticated execution to move large volumes quickly.
Can Joint Yen Intervention Hold Off the Speculators?
How well can two governments hold off a pack of determined currency speculators? The short answer is pretty well, but not forever. The joint intervention pushed the yen from 162.80 to 157.80 per dollar almost immediately.
Think of it like two big kids stepping onto the playground — the bullies backed off fast. Speculators held roughly $12.5 billion in bets against the yen before the move.
The intervention triggered the largest short squeeze in nearly two years. However, analysts warned that without real policy changes, like closing the interest-rate gap, any gains would likely fade quickly.
Central bank rate changes and interest-rate differentials are key determinants of whether such intervention can deliver lasting results.
