Japan is the fuse, not the firework.
Keep rates low, the yen melts, import inflation bites, real wages fall, current account tightens.
Hike to defend the yen, JGBs reprice, mark-to-market carnage, the sovereign balance sheet wobbles.
That is the corner.
Debt ~250% of GDP, BoJ owns a mountain of JGBs, liquidity is optical not real. One serious bid-to-cover miss or a yank in term premium and the spell breaks.
The global risk is the yen carry. Trillions funded in JPY sit in USTs, tech, EM, credit. A violent yen snap or JGB vol spike forces de-leveraging. First the yen spikes, then everything else sells to meet margin. VaR goes off, basis blows out, cross-asset vol bleeds into equities.
What to watch
- USDJPY 155 to 170 is the danger zone, a disorderly round-trip is the tell
- 10y JGB near 2% with thin books, then liquidity air pockets
- Cross-currency basis and FX hedge costs for lifers, if they stop hedging USTs the dollar buckles
Playbook for adults
- Cut JPY-funded leverage, reduce anything that lives off free carry
- Own convexity, long vol over hero trades
- Quality duration with hedge, not YOLO beta
- Real assets as anti-dilution, gold and BTC on a barbell with cash
- Energy and cash-flow over story stocks
This is not doom tweeting, it is plumbing. Japan is choosing between currency devaluation and bond devaluation. Either path transmits globally through the yen carry. When the quietest market in the world gets loud, every other market listens.