The Bid & Ask

Quotations, Dispatches, and the Daily Tape

Thursday, August 13, 2026

Rejected thesis

Death cross + volume confirm + deep drawdown → strong long signal

The result

Code: research/ma_cross.py, research/death_cross_refine.py Reports: research/ma_cross_report.json, research/death_cross_refine_report.json

Top line: The textbook reading of a death cross (SMA50 < SMA200) is bearish; empirically it is strongly contrarian. The death cross fires after a stock has already underperformed for months — by the time the MAs cross, the bottom is typically near. Stratifying by drawdown at the cross sharpens the edge dramatically:

Bucket (death cross) n 60d edge 120d edge 250d edge
death_all 14174 +2.6 % +2.4 % +4.2 %
death_vol_confirm 4600 +4.8 % +5.4 % +11.5 %
death_vol_confirm + dd ≤ -30% 1199 +15.9 % +19.4 % +44.6 %
OOS 2020+ vol_confirm + dd ≤ -30% 863 +20.2 % +22.3 % +57.4 %
Pre-2020 IS vol_confirm + dd ≤ -30% 336 +5.0 % +9.9 % +8.7 %

OOS edge is larger than IS — the signal didn't decay across the sample. Caveat: deep-drawdown cohorts carry survivorship risk (stocks that delist before the cross don't show up); the +57 % edge is likely an upper bound but even after a 30-40 % haircut for that bias the edge dwarfs every other cohort we have.

At a glance
Validatorresearch/ma_cross.py
VerdictRejected

Every result here is reproducible from the script named above. Reports are in the repository.

Other rejected theses