Cluster smoke w7b4p showed 44864 closed trades in 1M events at 200ms
latency — physically impossible without sub-cost churning. Root cause:
sl_distance = max(pnl_ema_loss, atr) ≈ 0.05 at cold-start, but round-trip
cost = 2 × 0.125 = 0.25. Every stop-out guaranteed loss > 5× distance;
EMA converges sub-cost.
Amendment: triple-max sl_distance = max(pnl_ema_loss, atr, 2*cost);
trail_distance = max(pnl_ema_win, atr, 2*cost). cost is an ISV-discipline
strategy anchor (already per-backtest from P4 — no new state slot, no
tuned constants). Added cost_per_lot_per_side_per_b param to both decision
kernel signatures and threaded cost_per_lot_per_side_d through both launch
sites in step_decision_with_latency.
Test: cost_floor_prevents_sub_cost_stops validates unrealized in (ATR, 0.25)
does NOT fire SL; unrealized > 0.25 DOES fire. Spec amended (§10, §12).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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