Corrections
Corrections are made within 30 days of a verified factual error and logged here permanently.
A correction improves the record and costs the author some credibility. That trade is accepted here because the record matters more.
| Date | Study | What was wrong | What changed | Flagged by |
|---|---|---|---|---|
| 11 Oct 2026 | Insider-buying edge | An earlier version of the pipeline claimed to exclude 10b5-1 plan transactions. It never did: the flag lives in the SEC’s SUBMISSION table and the code looked for it in the transactions table, where it does not exist, and the reader silently dropped the missing column. | The filter is now applied where the field actually is. It exists only from 2023 Q1 (13 of 81 quarters) and removes 3.89% of filing-owner records in those quarters. The two eras are therefore not filtered alike, and the post says so. | Author, before publication |
| 11 Oct 2026 | Insider-buying edge | An earlier draft claimed the 63-day horizon told the same story as the 21-day one (2017–2026: −0.41%, t −0.71). | Withdrawn. On the corrected screen the 63-day figure is +0.93% (t 1.45), the opposite sign, and the sign of that 2,715-event result is set by 66 observations. No claim is made about the three-month horizon. | Author, before publication |
| 16 Oct 2026 | Disposition effect; portfolio-driven disposition effect | reproduce.py and pdde/reproduce_pdde.py downloaded the CC0 panel with Python’s default client, which Harvard Dataverse refused with HTTP 403, so a clean checkout could not fetch the data. | Both scripts now send an explicit User-Agent and write to a temporary file first; the downloads in volmom/ send the same User-Agent. Re-run end to end from fresh downloads: no figure changed. | Author, on re-run |
| 16 Oct 2026 | Volatility-scaled momentum | volmom/reproduce_volmom.py labelled per-side breakeven costs “round-trip”, printed K7 FAIL for all three specifications, and described the 10% drawdown limit as applied. | The script now prints per-side and round-trip breakevens, compares the round trip with K7’s 0.50% floor (S1 pass, S2 fail, S3 pass) and says the limit is counted, not applied. In volmom/README.md the S2 round trip now reads 0.467% (the script’s figure; 0.468% was a doubling of a rounded number), the holdout coverage reads 84.8% as the script prints on a fresh download (85.0% could not be reproduced), and the replication window is labelled November 1927 – December 2011. No computed number changed; the verdict, no specification passes all four, is unchanged. | Author, on re-run |
| 17 Oct 2026 | Portfolio-driven disposition effect | The headline said retail traders’ preference for selling winners was “about twice as strong on days their other holdings were mostly down” (ratio 2.041). A pre-registered robustness test that compares each trader with themselves at the same holding day gives 1.03 (95% CI 0.95–1.13), and the specification the study used reports an effect of similar size in synthetic panels that contain none. The headline claim is not supported. | The title, summary, list entries, page description and social card now say the headline did not survive a stricter test. A dated correction box sits at the top of the study and the robustness update is in its body; the original figure is kept there, marked as corrected. The replication verdict recorded on 10 Oct 2026 is kept as the record of what was run; it no longer supports the headline. | Author, pre-registered robustness check |
Robustness disclosures
A later test that qualifies a published result, without showing a published figure or claim to be false, is listed here and in the study’s Versions section. These are not counted as corrections.
| Date | Study | What was added |
|---|---|---|
| 17 Oct 2026 | Disposition effect | A pre-registered test of whether the effect survives when holding age is held fixed, prompted by a method finding on synthetic data. The direction survives; the size depends on how “gain” is timed, and a V-shaped selling pattern is not ruled out. No published figure changed. Two sentences that read as stronger than this now say so: “not an aggregate artifact” and “the honest magnitude”; the study’s Versions section lists the wording. |
Complaints log
| Date | Complaint | Outcome |
|---|---|---|
| None received as of 17 Oct 2026. | ||
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