Japan plans to revamp $1.3 trillion FX war chest for yen intervention

Japan will study ways to improve management of its $1.3 trillion foreign exchange reserves, a draft growth strategy shows, as Tokyo seeks higher returns on its intervention ammunition while grappling with strained public finances.

The proposal, part of Prime Minister Takichi's policy agenda, marks a potential shift in how Japan deploys its FX Special Account — the primary tool for yen-buying interventions. The Ministry of Finance has already spent about $70 billion over the past two months to prop up the currency, with backing from US Treasury Secretary Scott Bessent, yet the yen has continued to weaken.

"The government will study improving the management of public sector-held assets, including the FX Special Account, and explore more effective use of these assets while considering their original purpose," the draft strategy states.

The yen briefly rallied to 156 against the dollar after the intervention campaign began but has since slumped past 161, underscoring the limited impact of currency defense when fundamental drivers remain unfavorable. Japan's debt load, at about 230% of gross domestic product, is the highest among advanced economies, while the US-Japan interest rate differential continues to weigh on the currency. The 30-year Japanese government bond yield has climbed to nearly 4%, the highest in more than a decade, reflecting growing investor concern about fiscal sustainability.

Why Returns Matter

The push to boost returns on the FX Special Account comes as Takichi's administration pursues aggressive fiscal spending to support the world's fourth-largest economy. Higher income from reserve assets could help offset widening budget deficits without additional borrowing. Japan's reserves, among the largest globally, are predominantly held in US Treasuries and other highly liquid sovereign debt, which currently offer yields well below what riskier assets might generate.

Any rotation away from traditional safe-haven holdings could have implications for global bond markets. Japan is the largest foreign holder of US government debt, and a shift in its reserve allocation strategy might reduce demand for Treasuries at a time when the US fiscal deficit is already pressuring yields higher.

Intervention Limits

The yen's persistent weakness despite $70 billion in intervention highlights the structural challenges Tokyo faces. Japan's current account surplus — one of the world's largest — has historically provided a buffer, but the scale of capital outflows from Japanese investors seeking higher yields abroad has overwhelmed that cushion.

"The intervention has failed to move the needle very much," said Desmond Lachman, a senior fellow at the American Enterprise Institute. "After briefly rallying to 156 yen to the dollar, the yen has again slumped to over 161."

Without fundamental changes to Japan's fiscal position or a narrowing of the US-Japan rate gap, currency intervention alone is unlikely to reverse the yen's trajectory. The draft strategy's focus on reserve management suggests Tokyo is exploring every available tool, but analysts say structural reforms — including generating primary budget surpluses — would be needed to restore investor confidence and support a sustainable yen recovery.

This article is for informational purposes only and does not constitute investment advice.