Market data normalisation

Venues do not share a vocabulary. One book says fair price, another markPx, another oracleMark. EPIC keeps the raw label and maps it to a canonical field: mark price, index price, last trade, reference price, funding interval, collateral, settlement, margin mode.

The mapping stores raw value, normalised value, method, source and reviewer status. In this demonstration the reviewer status is always unreviewed, because nobody has checked the rows against a real rulebook.