The immediate catalyst for the latest sharp decline remains difficult to identify with precision, but the broader story behind the yen has changed noticeably since the middle of last week, and several forces are now pulling in the same direction.
-
USD/JPY finally broke 155 on the third attempt, a level that had already survived two intervention-driven tests and had become a major psychological marker for the market.
-
The yen is now benefiting from a rare alignment of forces: more pressure from Washington for a stronger currency, expectations of a faster BOJ tightening path and renewed speculation that Japanese capital could be pulled back home.
-
The break matters, but it is still too early to call a full trend reversal. A lot of good news for the yen is already sitting in the price, and several of the assumptions behind the move remain untested.
Three times is a charm, and in FX that happens more often than people think.
The third test is not necessarily more likely to break simply because it is the third test. The first two successful defences are what establish that the level matters. What changes is what starts accumulating around it: more traders recognize the line, more positions get built against it, more stops gather behind it and more breakout players wait on the other side.
It is not a statistical law, but the idea has stuck with me since my first days trading USD/JPY for a Japanese bank, where the head trader was so superstitious about big figures and repeated tests that I nicknamed him “Tokyo’s big-figure oracle.” He believed the third proper test was often the one that mattered, and once a major USD/JPY level finally gave way, the market rarely looked back until the underlying regime itself began to run out of gas. Dark Side of the Boom.
USD/JPY finally broke below 155 on September 7 after twice surviving around the same area following intervention during Golden Week and again at the end of July. By early trading on September 8, the pair was below 154.50, and once the market pushed through roughly 155.50, the level that had marked the lows after both intervention episodes, another yen disappeared rather quickly.
That is what makes this break more important than the headline move itself.
Markets remember levels, especially when they have been defended more than once. The first test can be dismissed as noise, the second starts to build conviction, and by the third the market has often accumulated enough positioning around the idea that the floor will hold again. When it finally gives way, the move can accelerate because traders are not only reacting to fresh information; they are unwinding the confidence they had built around the level.
US Treasury Secretary Scott Bessent has become increasingly forceful in his comments about Japan’s fiscal and monetary policy, arguing around the G20 that Japan should move away from its reflationary stance and saying he was confident the government and the BOJ would take steps that would ultimately produce a stronger yen.
The timing was striking because Japanese ministries had just submitted FY27 budget requests totalling roughly JPY143 trillion, well above the current fiscal year’s initial budget of around JPY122 trillion, reinforcing the image of a still highly expansionary fiscal backdrop. Bessent’s comments may simply have coincided with the release of those figures, but in markets timing often matters as much as intent.
The message overseas investors heard was straightforward enough: Washington wants a stronger yen, and Tokyo may have less room than before to ignore that preference.
That perception has been reinforced by reports that Bessent had already voiced frustration over Japanese economic policy during his visit in May and by the broader belief that the coordinated intervention at the end of July was carried out with US cooperation. Whether every detail of that story is correct is almost secondary to the fact that it has given global investors a political framework for expecting a shift away from the reflationary policy mix that helped keep the yen weak for so long.
Bessent met Governor Kazuo Ueda on the sidelines of the G20, with the US Treasury later stressing the importance of monetary policy communication, inflation expectations and avoiding excessive exchange rate volatility. Ueda then kept the September 17 to 18 meeting firmly in play by saying a rate hike would be discussed thoroughly at every meeting, including the next one.
BOJ board member Hajime Takata added to that shift by arguing that the Bank should be prepared to raise rates nimbly rather than feel bound by the pace already anticipated by markets. He later pushed back against expectations for a larger move at the coming meeting, but by then the market had already absorbed the important part of the message: the BOJ may be willing to move faster than investors had assumed.
That matters because bullish USD/JPY had spent most of the summer resting on one very comfortable foundation: US rates stayed high, Japanese rates stayed low, carry paid and yen rallies struggled to survive.
Now that policy gap may be narrowing from both sides.
The third leg of the story is less certain, but potentially much larger.
Speculation has returned around a possible change in the Government Pension Investment Fund’s asset allocation. GPIF manages roughly JPY300 trillion, which means even a modest shift toward domestic financial assets could have a meaningful effect on Japanese markets and the yen.
The issue had already surfaced in July when Finance Minister Satsuki Katayama said the government wanted to explore ways to encourage GPIF and other pension funds to invest more heavily in Japanese financial assets. Interest picked up again after the GPIF Board of Governors met on August 21, and the agenda later showed discussion of the Basic Portfolio Review Project Team.
The fact that this was reportedly the first August Board meeting in around seven years only gave the market more room to speculate.
At this point, nobody knows whether a meaningful allocation change is actually coming. Details of the discussion may not emerge for months. But markets do not always wait for certainty, particularly when the institution involved is managing JPY300 trillion.
The possibility of capital being reshored back into Japan is enough to matter.
And it arrives just as the dollar side of USD/JPY is beginning to look less convincing.
The August employment report was strong, with nonfarm payrolls rising by 162,000, enough to restore some probability of another Fed hike. Yet the dollar response was surprisingly subdued, which is a useful signal in itself. A payroll print that strong would normally be expected to produce a more forceful move in the greenback, especially with the market already debating a September hike.
Instead, the dollar struggled to gather momentum.
Partly because Fed officials, including Christopher Waller, have made it clear they want to see the September 11 CPI before making a final judgment. Wage growth also slowed to 3.1% year on year, continuing its gradual downward trend and taking some of the urgency out of the argument that the labour market is generating another wave of inflation pressure.
So payrolls strengthened the case for a hike, but they did not settle it.
President Trump has also been pushing hard in the opposite direction, calling for lower rates and threatening illogical Trumponian moves if the Fed refuses to cut. A rate cut at next week’s meeting would be extremely difficult to justify against the current data, but the political message is clear enough: the White House does not want another round of tightening.
That has helped cap the dollar; at the same time, Japan-specific factors have started to favour the yen, and that is why this move feels different from the previous intervention-driven rallies.
The pressure is now coming from both sides of the cross.
Japan is becoming more hawkish, or at least being perceived that way, while the dollar is finding less support from what had previously been one of its strongest arguments.
Technically, the break below 155 is significant because USD/JPY also slipped beneath the 38.2% retracement of the rise from the April 2025 low above 139.50 to the July 2026 high just below 164. That brings the January low below 152.50 and the 50% retracement area above 151.50 into view.
If long USD/JPY positions built around the old carry regime continue to unwind, the pair has room to probe lower.
And unless USD/JPY can recover quickly above 155, the market may begin treating the old floor as the new ceiling.
That would be a meaningful shift, but it still does not automatically amount to a full trend reversal.
A lot of what has powered the recent yen move rests on expectations that have not yet been fully tested: a faster BOJ, less reflationary Japanese policy, possible GPIF repatriation, Washington’s preference for a stronger yen and a Fed that stops short of becoming materially more hawkish.
That is a lot of good news already sitting in one trade.
So the third attempt has finally broken 155, and that deserves respect.
But the bigger question is whether the market has simply kicked through a stubborn technical door or whether Japan is genuinely beginning to change the policy architecture on the other side.
In FX, those are two very different trades