# Data Dictionary - Hyperliquid Instrument Master - survivorship-bias-free perp listing registry

**Units:** stated per column in the descriptions below (this is a relational table; columns mix units).

| column | type | description |
|---|---|---|
| `coin` | str | Coin / perp ticker (primary key) |
| `first_seen` | str | First snapshot date the coin appears (YYYY-MM-DD) |
| `last_seen` | str | Last snapshot date the coin appears (YYYY-MM-DD) |
| `listing_ts` | str | Listing date (= first_seen) (YYYY-MM-DD) |
| `delisting_ts` | str | Delisting date (= last_seen if delisted, else null) |
| `status` | str | active or delisted (delisted = last_seen < archive max date) |
| `market_type` | str | Market type (perp) |
| `n_days` | int | Number of distinct days the coin was observed |

*Source: Hyperliquid (on-chain perpetual DEX) - public asset-context data.*