The HIP-4
protocol map.

One outcome, several identifiers.

Hyperliquid defines an outcome encoding as 10 × outcome + side, where side is 0 or 1. That encoding appears in different wrappers depending on the API field. Treat them as typed identifiers, not interchangeable labels.

These identity rules are documented in Hyperliquid's official Asset IDs reference.

Probability-shaped prices, CLOB execution.

An outcome price between 0 and 1 is commonly read as an implied probability, but it is still a market price. Depth, spread, inventory, and information all affect it. Orders execute through HyperCore's limit-order-book mechanics rather than a prediction-market AMM.

For a binary market, Yes and No are separate contracts. Do not assume a displayed pair will always sum to exactly 1.0 at executable size: bids, asks, spread, fees, and stale books matter.

Binary, multi-outcome, recurring.

Winning outcomes settle to 1.0.

When a market resolves, winning contracts settle at 1.0 and losing contracts at 0.0. The account balance updates automatically; there is no separate claim transaction in the normal HIP-4 settlement flow.

Resolution quality depends on the market's specification and settlement source. A short title is not enough. Traders should inspect the full question, cutoff time, source, tie/void behavior, and any dispute process exposed by the venue.

Mainnet trading and testnet launch are different tracks.

Curated outcome markets trade on mainnet. Permissionless Standard-mode deployment is currently a testnet workflow with stake, activation, venue-name, template, and rate constraints. Hyperliquid now documents outcome asset IDs, but no single public specification covers every observed creation, taxonomy, and settlement form. Production integrations should validate behavior against live API responses.

Primary sources