The Bid & Ask

Quotations, Dispatches, and the Daily Tape

Thursday, August 13, 2026

Rejected thesis

Earnings-reaction reversal (anti-PEAD)

The result

Thesis (rejected): When a name misses consensus by ≥ 10 % AND drops ≥ 7 % on the print, the market overreacts and the stock bounces over the next 5-10 trading days. Mirror image of the PEAD signal that works on beats.

Code: research/earnings_reversal_validate.py Report: research/earnings_reversal_report.json (n=489 events)

Why it failed: The bounce doesn't materialize. Edge is essentially zero at every horizon we measure:

Horizon Event mean Ctrl mean Edge Hit
5 d +0.3 % +0.4 % -0.1 % 52 %
10 d +0.3 % +0.3 % +0.0 % 52 %
20 d +1.4 % +0.6 % +0.8 % 52 %
40 d +0.7 % +1.7 % -1.0 % 49 %
60 d +3.9 % +3.5 % +0.4 % 54 %

Asymmetry finding: positive surprises underreact (PEAD: +2.8 to +5 % edge at 20 d) but negative surprises are priced more efficiently. Bad-earnings drops are typically structural (the company actually got worse) rather than panic overshoots, so the bounce-on-mean-reversion mechanism that works for generic crashes (our bounce cohort) doesn't extend to earnings-catalysed crashes.

Verdict: Cohort skipped. Useful confirmation that our generic bounce cohort works because it isn't earnings-catalysed - oversold + volume on technical / sentiment grounds is a different beast from oversold-on-bad-news.


At a glance
Sample489
Validatorresearch/earnings_reversal_validate.py
VerdictRejected

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

Other rejected theses