The Bid & Ask

Quotations, Dispatches, and the Daily Tape

Thursday, August 13, 2026

Rejected thesis

Golden cross (lagging trend confirmation)

The result

Thesis (rejected): When the 50-day SMA crosses above the 200-day SMA, the stock is in a confirmed long-term uptrend and continues higher for 1-12 months. Mirror image of death cross.

Code: research/ma_cross.py Report: research/ma_cross_report.json (n=13,243 golden crosses on the US universe, 2010-2026)

Why it failed: Edge is ~0 across every horizon and every variant (fresh, volume-confirmed, 200-DMA-rising).

Bucket n 20d edge 120d edge 250d edge
golden_cross_all 13243 -0.13 % +0.11 % -0.72 %
golden_fresh 9102 -0.21 % +0.52 % -0.57 %
golden_vol_confirm 2754 -0.08 % -0.00 % -0.54 %
golden_fresh+vol 1927 -0.08 % +0.83 % -0.20 %
golden_slope_up 5015 +0.05 % -1.21 % -1.95 %

By the time SMA50 has risen above SMA200, the bulk of the move is already in the price. The cross is lagging confirmation, not a predictive signal.

Verdict: Skip. The complement — death cross — turns out to be the useful direction (see Working signals).


Working signals — discoveries from this batch

These are not nulls, but documenting them here so the negative results above have context for what we kept. Full write-ups when each gets productized.

At a glance
Sample13,243
Validatorresearch/ma_cross.py
VerdictRejected

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

Other rejected theses