# Rule Change Log

## 2026-06-15 - Introduce `ipo_score_v0`

Request:

- Start digesting the downloaded IPO archive and build the first analyst model.

Change:

- Added `rules/ipo_score_v0.yaml` as the initial transparent scoring baseline.
- Added `scripts/build_analysis_dataset.py` to generate a feature dataset and calibration report from `data/hk_ipo.sqlite`.
- Added `data/snapshots/analysis_model_v0_dataset.csv` as the first model-ready snapshot.
- Added `reports/2026-06-15_analysis_model_v0.md` to document coverage, calibration, and known gaps.

Rationale:

- The archive now has enough T0 facts and D1/D5/D20/D60 labels to support a repeatable baseline.
- T1 demand data is partially structured and highly informative where available.
- T2 grey-market data remains blocked until a reliable source exists, so it is excluded from v0.

Verification:

- Generated the dataset from the current SQLite archive.
- Confirmed the model keeps post-listing returns as labels only.
- Recorded non-monotonic middle buckets as a limitation rather than overfitting them away.