Test set (Sep 2023 - Dec 2024): only S9_Filtered passes (PF=1.13),
portfolio PF=0.91 FAIL. S3 expansion to GBP_USD, EUR_USD, GBP_AUD
shows no generalization — GBP_JPY remains the only viable pair.
No strategy is consistently profitable across all 4 validation periods.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>