Why euros, and why nowThe yen had been trading at near 40-year lows against the dollar heading into August. When the world’s reserve currency issuer shows up on the same side of a trade as Japan, speculators tend to pause and reconsider. Euros offered a workaround: stabilize the yen, keep the dollar narrative intact, and quietly discourage Tokyo from dumping American debt. The last time this happenedThe last coordinated US foreign exchange intervention occurred in 1998, when the Treasury bought yen during the Asian financial crisis. By selling euros instead of dollars, the US effectively told Japan: we’ll help you stabilize your currency, but don’t do it by dumping our debt.