Methodology

How HEI classifies records

Historical Exchange Index is a historical registry, not a live ranking product. It tracks exchange identity, status shifts, major lifecycle events, URL history, and supporting records in a structured, archive-aware format.

Core principles

Registry first

HEI is designed as a registry, not as a recommendation or ranking surface.

Entity-first

v0 counts entities, not deployments. Multi-chain deployment splitting is deferred.

Archive-aware

Dead-side records prefer archived references when live domains are unsafe or repurposed.

Uncertainty visible

Unknown values are preferred over forced weak conclusions.

Record model

Entity

The exchange itself: identity, aliases, status, dates, origin, domain history.

Event

Meaningful lifecycle changes: launches, shutdowns, hacks, insolvency, rebrands, acquisitions.

Evidence

Supporting records used to back claims: official references, archival captures, reporting, and notices.

Status handling

HEI separates exchange status from disappearance cause. A record can be dead, merged, acquired, rebranded, limited, inactive, or active, while the reason field separately describes why the record reached that state.

URL handling

Original domains are historical records, but not always safe destinations. HEI tracks URL status separately and may prefer archived URLs over live domains when the original property has died, redirected, been repurposed, or become unsafe.

Revision policy

Records may be incomplete, approximate, contested, or revised. Dates, causes, and classification details can change when stronger evidence becomes available.

HEI is intentionally conservative. It is better to leave a field uncertain than to overstate a claim with weak support.