The watch dashboard
The book argues Japan can hold only two of three goals — cheap debt service, a defended yen, normalized rates — and that the choice of which to sacrifice is legible in a handful of readings. These are those readings.
Paperback, out now. Prisoners of the Yen in English, 円の囚人 in Japanese. In Japan: English · 日本語版.
Scored in the matrix
USD/JPY, four-week change
—%
USD / JPY
—
BOJ policy rate
1.25%
Japan core CPI, y/y
1.7%
10-year JGB yield
—%
JGB 10s30s slope
—pts
UST 10s30s slope
—pts
Nikkei, from its 60-day high
—%
Context — argued in the book, not scored
Nikkei 225
—
Gold, $/oz (COMEX)
—
Gold, ¥/oz
—
Bitcoin, $
—
Fed − BOJ policy spread
2.625pts
Japan gross debt
205% GDP
Market series: end-of-day closes, refreshed every 15 minutes. Policy and CPI readings are updated by hand after each release.
Reading the tape
Each row is an indicator; each column is the road it would point to. Track two above all: the yen's rate of change and the real policy rate — the Bank's rate less Japan's core CPI. Not the yen's level, which cannot tell credibility from liquidation, because both print a stronger yen. Fiscal stance is the swing that turns a given combination into A, B, or C.
| Indicator | Case A · consolidation | Case B · debasement | Case C · fiscal dominance |
|---|---|---|---|
| USD/JPY, four-week rate of change (two-tailed) | Calm — under 2% either way, the level holding because policy is credible | 2–10% in either direction, sustained | 10% or more in either direction: weakness forces intervention and Treasury sales, strength forces the carry unwind |
| USD/JPY, post-intervention | Firm and quiet — strength earned by discipline, not by positions closing | Drifting weaker on the rate gap | Defended by intervention rather than rates; FIMA-dependent, capital-flow measures appear |
| BOJ hike path vs. Japan core CPI | Hikes keep pace with or lead inflation | Hikes persistently lag inflation | Hikes halted or reversed despite an above-target print |
| 10Y JGB yield & term premium | Compresses on restored credibility | Elevated but orderly | Disorderly spike — or any new yield cap or purchase guidance |
| Long-JGB demand — 10s30s slope | At or below its ten-year median, 0.77pts | Soft but functioning | 1.37pts or steeper — above the 95th percentile of the last decade; the super-long being abandoned |
| US duration — 10s30s slope | At or below its ten-year median, 0.44pts | Drifting with the US fiscal story rather than Japan’s | 0.75pts or steeper — the long end underperforming on forced, price-insensitive selling |
| Fiscal stance | Primary-balance target restored; supplementary budgets shrink | Supplementary budgets stay large; debt-ratio metric retained | Spending sustained and the BOJ made to fund it |
| BOJ–government relations | Independent, cooperative | Quietly accommodative | Open friction; pressure on independence |
| Japan real wages vs. CPI | Positive — relieves pressure | Negative — sustains the squeeze | Sharply negative — a political forcing event |
Reading the live feed against the matrix…
Current reading — 24 September 2026. Case B, unbroken. The Federal Reserve raised 25 basis points on the 16th and the Bank of Japan matched it on the 18th, 7–2, to 1.25%, effective the 24th. Because both moved, the policy differential ends the cycle where it began, at 2.625 points. With core CPI at 1.7%, the real policy rate is −0.45%, and the BOJ's own forecast has inflation rising clearly above 2%; a central bank that keeps hiking is still behind. Real wages have turned positive, up 2.4% in July from a year earlier, the seventh straight gain, so that row moves from B to A; one row doesn't move the case. Tokyo's first session with the new rate in force went the wrong way for a hike: the ten-year JGB touched 3.055% intraday, its highest in about 30 years, JGB futures tripped the Osaka Exchange's circuit breaker, and the yen traded near 158.7. On the Finance Ministry's constant-maturity measure, the ten-year closed at 3.073%, up 3.1% on the day and still inside the 5% line. Much of the pressure came from New York, where the ten-year Treasury is above 5.1%. The yen is 0.4% firmer over four weeks, back in the calm band after touching 152.90 on 8 September. The Nikkei closed at 65,514, up 495 points from the 18th, without the yen surge that marks a carry unwind. Fiscal policy stays expansionary: the FY2027 requests book debt service 17% higher. The tell that would move the reading to Case C is still not a weaker yen. It is any re-imposition of yield caps or purchase guidance, or a four-week yen move of 10% in either direction. The Bank of Japan decides again on 30 October.