With the nightly SIP backfill making all BASELINES consolidated-scale, the still-IEX live
ingest would make Monday's RVOL read iex_intraday/sip_baseline ~= 25-50x too LOW and choke
the scanner. Free-key SIP is only 15-min DELAYED, so each morning the true per-name capture
ratio is directly measurable:
- research/ingestion/volume_ratio.py: compute_ratios fetches BOTH feeds for the identical
embargo-capped window (never vs our DB bars — those are scaled; that would double-correct);
guardrails (min samples, clamp [1,300]); persist_ratios records per-day ratios.
- ingest_live_minute_bars(volume_scale=...): scales bar volumes per symbol at ingest, marks
source_provider=alpaca_iex_scaled. Missing symbol -> 1.0 (conservative: reads LOW, blocks).
Constant per-symbol scale leaves cumulative VWAP unchanged (cancels in the weighted mean).
- run_live_paper: "vratio" step every 300s (VOLUME_RATIO_ENABLED/INTERVAL) merges fresh
ratios (a name gone thin keeps its last good ratio); step_ingest applies them.
- premarket_eval nightly audit: snapshots the day's scaled ESTIMATES before the SIP truth
overwrites, then logs median/worst error to data/volume_estimator_audit.tsv — the
estimator's accuracy is self-measured daily, which is exactly the evidence that decides
whether the $99/mo real-time SIP plan is ever needed.
Live check (2026-07-02 full session): ratios are hugely name-dependent — DSY x300(clamped),
CETX x286, SOFI x45, SNDQ x42, NOK x17 — validating per-name daily measurement over any
global constant. 3 pure unit tests (ratio math + thin-sample skip; ingest scaling + provider
marking; no-ratio unchanged).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
