The move also underscores how rapidly concern has grown over the yen’s collapse and how the US could be impacted as President Trump has pursued sweeping trade deals with Sanae Takaichi’s government in Tokyo. <\/p>\n
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“The decision to launch intervention on July 30 should reflect a strong determination by the authorities to support the yen,” Bank of America FX strategist Shusuke Yamada said in a note on Monday. “Moreover, the fact that the operation was coordinated suggests that extensive currency diplomacy took place beforehand.” <\/p>\n
In July 2025, the two countries announced a widely scoped trade agreement that shifted their economic relationship away from a traditional free-market model and toward the tariff-led arrangement President Trump has sought from partner nations. <\/p>\n
The landmark agreement reduced the tariff on most Japanese imports to 15%, down from the previously threatened 25%, in exchange for a broad package of Japanese concessions. Tokyo pledged up to $550 billion in investment into strategic US industries \u2014 including manufacturing, semiconductors, energy, and critical minerals \u2014 while also agreeing to expand purchases of US agricultural products, energy exports, aircraft, and defense equipment. <\/p>\n
Since then, the agreement has been implemented through a series of smaller project announcements. In February 2026, Washington and Tokyo unveiled the first roughly $36 billion of investments under the framework, including a major gas-fired power plant, a deep-water crude oil export terminal, and an industrial diamond manufacturing facility. A second round announced in March 2026 expanded the partnership into additional natural gas infrastructure and small modular nuclear reactor projects. <\/p>\n
A weaker Japanese currency could complicate that trade, as a declining yen raises the cost of imports for Japanese buyers while intensifying inflationary pressures in a nation already struggling to tame inflation as the Bank of Japan keeps target rates at ultralow levels, well below other G7 nations. <\/p>\n
The move also comes at a pivotal moment for the US government bonds market. <\/p>\n
After the Federal Reserve voted on Wednesday to keep the US target interest rate unchanged, yields on 30-year Treasurys climbed to decades-long highs, crossing 5.20 to reach the highest levels seen since 2007. Japan is the largest foreign holder of US Treasurys, and any sustained selling of the government bonds could pressure yields even higher. <\/p>\n
The Bank of Japan has access to the Foreign and International Monetary Authority Repo Facility (FIMA Repo Facility), which allows certain central banks to use Treasury holdings as collateral to borrow dollars, rather than liquidating Treasurys for cash. <\/p>\n
That option, which Bessent encouraged on Sunday, could help alleviate concerns about Japan’s selling of Treasury Holdings, though it wasn’t clear on Monday exactly how the Bank of Japan had funded its yen purchases. <\/p>\n
“The degree to which both governments have presented a united front is notable, both in emphasizing the potential firepower behind Japan’s yen-buying intervention and in limiting any adverse impact on the U.S. Treasury market,” Bank of America’s Yamada wrote. <\/p>\n
Rather than selling dollars outright, the Treasury Department reportedly sold euros held in its Exchange Stabilization Fund to finance the purchases of yen. Strategists said the approach allowed Washington to support Japan’s currency without sending an explicit signal that it wanted a weaker dollar \u2014 a message that could have complicated inflation expectations or Treasury markets as long-term yields remain near multidecade highs. <\/p>\n
That said, even with the decision by the US Treasury to sell euros, there may be limited room for further intervention by the US, according to JPMorgan strategist Junya Tanase. The US Treasury’s Exchange Stabilization Fund, designed for moves like that of the Treasury to prop up the yen, held roughly $13 billion of euro-denominated assets and roughly $25.5 billion of dollar-denominated assets at the end of June, per Tanase. <\/p>\n
It’s unknown exactly how much the Treasury Department spent in this round of intervention, but the size of its reserves earmarked for such moves is relatively slim compared to earlier Japanese interventions in the yen, which were sized between $30 billion and $60 billion. <\/p>\n
Jake Conley is a breaking news reporter covering US equities for Yahoo Finance. Follow him on X at @byjakeconley or email him at jake.conley@yahooinc.com. <\/p>\n