Score/History
Every trading day, we archive the score each built-in preference gave to every ticker in our universe. Pair any day's scores with the next day's close price and see the 1-day return. No aggregation, no "accuracy" claims — raw data, honestly preserved.
How this data is captured: A daily cron runs at 23:30 UTC Monday through Friday, reads the closing snapshot, and writes an immutable per-day file for stocks and OTC. Every file's SHA-256 hash is recorded separately — if the archive is ever modified after write, the mismatch is detectable.
What's missing and why: Weekends and US market holidays have no entries. Days where the cron failed also have no entries — we never backfill, because backfilled data is no longer a snapshot of what our system would have said in real time. Gaps are a feature, not a bug.
Formula versions: Each record carries the scoring formula version that produced it. When scoring logic changes, we bump the version — old records keep their old version, users see both. We never retroactively re-score past records.