The dollar has had a rough week against the yen, and Tuesday brought no relief. USD/JPY dropped to around 152.87-153.34, the yen's strongest level since February, extending a slide that has now taken the pair down roughly 4-4.5% from above ¥160 just a week earlier. For anyone who closed out a short-yen position expecting a bounce, the timing could hardly have been worse.

The move has carried the pair beyond the levels reached after Japan and the United States jointly intervened in the currency market in July. Japanese authorities spent a record ¥15.4 trillion, or about $96.5 billion, defending the yen between July 30 and August 26. This time, however, monetary-policy expectations are doing most of the work rather than direct intervention. Finance Minister Satsuki Katayama has signaled that Tokyo and Washington remain closely coordinated on promoting orderly currency markets, but no fresh intervention has been confirmed even as the pair trades well beyond July's defended zone.

Much of the move reflects traders unwinding short-yen positions that had funded carry trades for months, borrowing cheaply in yen to buy higher-yielding assets elsewhere. Those trades worked as long as Japan's policy rate stayed far below its developed-market peers, but that gap is now closing quickly. Japan's second-quarter economic growth was revised higher to an annualized 1.4%, supported by stronger business investment, while real wages rose 2.4% year over year in July, the biggest increase since May 2021 and a seventh consecutive monthly gain. Improving purchasing power gives the Bank of Japan more room to tighten without choking off domestic demand.

Swap markets are now pricing in roughly a 98% probability that the BOJ raises its policy rate by 25 basis points to 1.25% at its September 17-18 meeting, with a further move to 1.5% fully priced in by January. That level of conviction is unusually high for a central bank that spent years anchored near zero, and it explains why yen bulls have kept pressing the pair lower even without fresh intervention headlines.

The dollar side of the equation is more complicated than a simple rate-differential story. August's US payrolls report showed 162,000 jobs added, nearly triple the 56,000 that had been expected, lifting the market-implied probability of a Federal Reserve rate hike this month to around 60%. Normally, that kind of data would support the dollar by widening the yield advantage on offer relative to yen assets. Instead, the dollar index slipped to a two-week low near 98.80, as fiscal concerns and caution ahead of this week's US inflation data limited any rebound.

That inflation data now looks like the pair's next major catalyst. US producer prices are due Thursday, followed by the Consumer Price Index on Friday. A hot set of readings could lift Treasury yields and spark a sharp dollar rebound before the BOJ even sits down to deliberate, while a soft print would remove one of the few remaining supports for the greenback and could accelerate the yen's advance toward the next major support band.

On the chart, ¥153 remains the immediate pivot, with layered support at ¥154.00, ¥153.50 and ¥153.00 giving way to a more significant zone near ¥151.30-151.50 if the decline continues. On the upside, resistance builds around ¥155.00, then ¥156.00, with the 200-day moving average near ¥158.00 marking the point at which the broader downtrend would need to be reconsidered. A sustained break below ¥153 would confirm the trend shift already underway; a hot US CPI print could just as easily remind traders that two central banks, not one, are currently auditioning for the hawkish role in this pair.

The carry-trade unwind adds a structural dimension that goes beyond this week's data calendar. Years of near-zero Japanese rates encouraged investors worldwide to borrow yen and redeploy the proceeds into higher-yielding currencies, equities, and credit markets, and estimates of the total outstanding carry position have run into the hundreds of billions of dollars. As the BOJ closes in on its most credible tightening cycle in decades, at least part of that unwind is likely still ahead rather than behind, which helps explain why the yen has strengthened so quickly even without a fresh intervention announcement. A disorderly acceleration of that process, rather than a gradual one, is the scenario currency desks are most focused on heading into the BOJ decision.

Japan's political backdrop adds another layer worth watching. Finance Minister Katayama's comments about close coordination with Washington suggest Tokyo wants to avoid the kind of one-sided yen move that could destabilize export-heavy sectors of the economy, even as officials appear comfortable letting monetary policy, rather than intervention, do the heavy lifting for now. Japanese equities with high overseas revenue exposure have historically been sensitive to sharp yen appreciation, since a stronger currency mechanically reduces the yen value of profits earned abroad, and that dynamic is likely to remain a talking point among Tokyo-listed exporters as the currency continues to test multi-month highs.

For currency traders, the net setup into Thursday and Friday is unusually binary. A hot US inflation print combined with a BOJ that still delivers its expected hike would likely produce two-way volatility rather than a clean trend in either direction, while a soft US print paired with confirmation of the BOJ's hawkish path would be the cleanest continuation signal for further yen strength. Either way, position sizing around this week's data deserves more caution than usual, given how much of the recent move already reflects expectations that have not yet been confirmed by an actual central bank decision.