Yen intervention is proving short-lived: lessons from April-May 2026 and 2024
History suggests official intervention buys time rather than reverses the trend. Tokyo deployed a record ¥11.7 trillion ($73.6 billion) between 28 April and 27 May, according to Ministry of Finance data, briefly pushing USD/JPY back towards 155-156. In both that 2026 episode and the comparable April-May 2024 round, the pair fully unwound the losses inflicted by intervention within less than two months.
Unless paired with a genuine shift in BoJ policy, intervention will continue to function as a circuit-breaker rather than a cure for yen weakness.
Can Japan afford to keep intervening? In principle, yes. Japan held $1.094 trillion (¥177.5 trillion) in foreign currency reserves as of end-May, according to Ministry of Finance data — enough to fund roughly 15 more rounds of intervention at the scale seen in April-May.
Whether it will is a separate question. Analysts estimate roughly 70% of Japan’s foreign currency securities are held in US Treasuries. With $31.52 trillion in US public debt outstanding as of May, Japan’s holdings are estimated at close to 2% of the market, meaning large-scale sales to fund yen-buying risk pushing up Treasury yields.
Intervention impact on USD/JPY