Every material change to the data or a published figure, newest first: with what caused it. This is the operational twin of the corrections page.
Why we keep this in public.
We publish statistics people may act on. A number is only trustworthy if you can see what happened the last time it was wrong. Nobody else in this category publishes a changelog. That is the point.
Reverted the conference study to its curated 1,425-event sample2026-07-13
We had grown it to 1,986 using an SEC-filing crawler. Measured recall showed the crawler sees only 38% of large-cap presenters vs 57% of small-caps; a poster is material to a $200M biotech (8-K filed) and immaterial to Merck (no filing). Adding those events re-weighted the study toward micro/small and moved the nano median for sampling reasons, not real ones. Full correction.
Corrected the PDUFA run-up figure: +0.57% → +0.43%2026-07-13
The published figure was computed on a catalyst panel containing 202 duplicate rows. Deduplicated, the median is +0.43% (n=1,661). The conclusion is unchanged; still within half a percent of zero, but the number was wrong.
Fixed a crawler that was inventing conferences that never happened2026-07-13
It resolved a conference name to that conference's next occurrence, ignoring the year written next to it, so a 2026 filing saying “presented at ESMO 2025” produced an upcoming ESMO 2026 event. Five phantoms. The rule now: a stated year always wins, and a past year can never produce a future event.
Repaired a data file that could not be read at all2026-07-13
The crawler wrote raw press-release text into CSV without escaping quotes. One " inside a snippet destroyed the file from that row to end-of-file. It now writes QUOTE_ALL and re-reads its own output, failing the build if the row count doesn't round-trip.
Restored a conference we had wrongly deleted2026-07-12
We pulled a row labelled “ANE” calling it a parsing artifact. It was a garbled ENA: the AACR-NCI-EORTC conference, which is real. Restored the 23 genuine October events; marked the rest unknown.
Stopped assigning market-cap tiers with hindsight2026-07-12
Every presentation had been bucketed by the company's market cap today. A company that was mid-cap in 2018 and has since collapsed was filed under nano, so the nano bucket was enriched with companies that later fell apart. Now computed as of the event date.
Retired one of our own models for being wrong2026-07-11
Our Conference Overlay claimed nano/micro presenters ran up +4.88%. Our own 1,425-event study found the nano median is negative. Refuted and retired.
Refused to publish our most quotable statistic2026-07-10
“68% of readouts do nothing” would have travelled. The bucket it came from spans −14.9% to +5.0%: a 20-point range is not “nothing.” We published the honest cut instead: 56.5% land within ±5%.
Rejected a bug report, and logged that too2026-07-10
A reviewer said our 1-day return column was mis-scaled and the 25th percentile was −521%. It is already in percent; the real figure is −5.19%. Acting on it would have corrupted our most valuable dataset. A corrections page that only shows the times we were wrong is marketing.
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