The GpuBacktestConfig hardcoded max_position=1.0 with a 2× leverage cap,
reducing effective position to 0.2026 contracts on ES at $35K capital.
Training uses max_position_absolute from PSO params (1.0-4.0 contracts)
with no leverage cap — a 5.4× mismatch that makes transaction costs
overwhelm any alpha in walk-forward evaluation (0% win rate, -688% return).
Fix: Pass max_position_absolute through evaluate_gpu() and disable
leverage cap (max_leverage=0) to match training conditions. Same fix
applied to evaluate_baseline.rs via --max-position CLI arg.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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