Broadened crypto universe 28 majors -> programmatic top-80 (64 usable), added
funding-coverage/history filter. Carry COLLAPSED (+0.82->-0.03) and stayed dead even
on broad-but-clean subset (fundcov>0.9, 45 coins): carry was cherry-picked to majors,
not robust. Cross-sectional MOMENTUM is the robust edge: XS_mom_30 IS+0.89/OOS+0.88,
CPCV-med +0.75, DSR 0.75, survives 2x cost, holds across 64- and 45-coin universes.
Momentum needs breadth (weak on 28 correlated majors). Same regime failure (2019/2022).
Methodology win: broadening killed a cherry-picked claim before a build.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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