# data/archive — frozen price records for deleted constituents

When a constituent leaves the index, the live price sources eventually stop
serving its history (Yahoo dropped ASM.AX entirely within weeks of its
delisting). The pipeline needs those closes to recompute any level from a
period that still held the name, so the record is frozen here, in the repo,
and published at /data/archive/<TICKER>.csv.

`backfill-history.py` and `test-continuity.py` read every `<TICKER>.csv` in
this directory automatically. Columns: date, open, high, low, close, volume —
local currency, exchange-local trading day. Only `date` and `close` are used.

## ASM.AX.csv — Australian Strategic Materials Ltd (ASX), 2026-04-20 … 2026-08-19

- 87 trading days; the only missing weekday is 2026-06-08 (King's Birthday,
  ASX closed). Last row 2026-08-19 is the final session before suspension.
- Source: stockanalysis.com ASX price-history pages for ASM, read directly from
  the rendered table on 2026-10-10 (two pages, 100 rows, of which the 87 from
  2026-04-20 on are kept).
- Closes: the page displays closes rounded to the cent; ASX stocks in this
  price band tick in half-cents. Exact closes were recovered by chaining the
  page's own day-over-day change column backward from the 2026-08-19 close
  (A$1.17, confirmed by the final quote Yahoo still serves) and snapping each
  step to the half-cent grid. Every recovered value rounds to the displayed
  close, and the chain reproduces the 2026-06-18 close (A$1.26) and the
  2026-04-30 close (A$1.55) already embedded in data/inception.json — three
  independent anchors, 86 steps, zero mismatches.
- Open/high/low/volume are as displayed (cent-rounded); not used by the index.