Intervention

Donald Trump extended the Israel-Lebanon ceasefire by three weeks on Thursday, pushing the 26 April expiry to mid-May. For speculators holding a yen short built to pay out on that discrete binary, the event has not dissolved; it has moved, into the same fortnight as Scott Bessent’s scheduled Tokyo stopover on his way to Mr Trump’s summit with Mr Xi in China. The shift matters because the dollar-yen floor at 160 is held not by any change in Japanese interest rates but by a new bilateral arrangement. Satsuki Katayama, Japan’s finance minister, threatens intervention; Mr Bessent, US treasury secretary, endorses her by declining to contradict her in public. This is the intervention-acquiescence model: US tacit consent to Japanese currency defence, in lieu of the January pressure on the Bank of Japan to raise rates. ...

There are two kinds of statement a finance minister makes: the spoken and the withheld. When America’s treasury secretary, Scott Bessent, met his Japanese counterpart, Satsuki Katayama, in Washington on 15 April, the unspoken carried the weight. When the two last met, in January, the Treasury’s readout noted that Mr Bessent “emphasized the need for sound formulation and communication of monetary policy”, diplomatic code for pressing the Bank of Japan to raise rates. That sentence is absent from the April readout. Ms Katayama, for her part, told reporters that the two ministers had not discussed monetary policy. ...

Japan’s budget passed. The ceasefire is collapsing. Katayama’s intervention window is open for the first time since she took office.

Predicting when a finance minister will intervene in the currency market is a fool’s errand. The MOF does not publish a schedule. The whole point of intervention is surprise: catching speculators wrong-footed, inflicting maximum pain per yen spent. Anyone claiming to know the date is selling you something. And yet. The decision to intervene is not made in a vacuum. It requires political clearance, diplomatic coordination and tactical conditions that do not appear on demand. These constraints are visible. They can be mapped against a calendar. The result will not be a date circled in red but a window, the period during which the political stars align and the MOF gains the freedom to act. ...