The Japanese yen surged against the US dollar, with intraday moves reaching as high as 3% on July 30, marking one of its largest single-day swings in years. The move sent a clear signal to currency traders: someone very large was buying yen, and that someone almost certainly had a government email address.
Japan’s Ministry of Finance and the US Treasury executed coordinated yen purchases on July 30 and 31, their first joint currency action since 2011. The intervention came after the yen had weakened to a 40-year low near ¥164 per dollar, a level that apparently crossed the pain threshold for policymakers in Tokyo and Washington alike.
The scale of Japan’s currency defense
Japan’s intervention spending has been nothing short of extraordinary. The country spent a record ¥15.39 trillion on yen purchases during July and August 2026, a figure that eclipses prior annual records for currency intervention.
To put that in perspective, that’s roughly $36 billion deployed to prop up a single currency over the span of weeks.
