HIP-4 prediction markets are currently live on testnet only. When they launch on mainnet, the same enrichment and action types will be available on the mainnet stream automatically.
Overview
HyperLiquid’s HIP-4 introduces prediction markets to the L1. hypernode captures all prediction market activity in real time, enriched with human-readable metadata.
Prediction markets consist of:
- Questions — A prediction with multiple outcomes (e.g., “Will BTC be above $67,579 on 2026-03-31?”)
- Outcomes — Individual tradeable outcome tokens within a question
- Price Binaries — A common type where the prediction is whether an asset exceeds a target price
User actions (5 types)
userOutcome
Place an order on an outcome token. Same format as a regular order but for prediction market outcomes.
splitOutcome
Split a position into individual outcome tokens.
{
"type": "splitOutcome",
"data": {
"outcomeAssetId": 1900001,
"amount": "100.00",
"prediction_outcome_id": 1900001,
"prediction_name": "BTC > $67,579",
"prediction_description": "class:priceBinary|underlying:BTC|expiry:20260331-0300|targetPrice:67579|period:1d",
"prediction_sides": ["Yes", "No"],
"prediction_question": "Daily Price Binaries",
"prediction_underlying": "BTC",
"prediction_expiry": "20260331-0300",
"prediction_target_price": 67579.0,
"prediction_period": "1d"
},
"network": "testnet"
}
mergeOutcome
Merge outcome tokens back into the underlying. Same structure as splitOutcome.
mergeQuestion
Merge all outcome tokens for a question.
{
"type": "mergeQuestion",
"data": {
"questionId": 42,
"amount": "50.00",
"prediction_question_id": 42,
"prediction_question_name": "Daily Price Binaries",
"prediction_question_description": "Will BTC close above the target price?"
},
"network": "testnet"
}
negateOutcome
Negate (flip) an outcome position. Same structure as splitOutcome.
When a HIP-4 event is streamed, the data field is automatically enriched with prediction market metadata. This metadata is fetched from HyperLiquid’s API and refreshed every 60 seconds.
Enrichment fields
| Field | Type | Description |
|---|
prediction_outcome_id | number | Outcome asset ID |
prediction_name | string | Human-readable outcome name |
prediction_description | string | Full description |
prediction_sides | string[] | Trading sides (e.g., ["Yes", "No"]) |
prediction_question | string | Parent question name |
prediction_underlying | string | Underlying asset (price binaries, e.g., "BTC") |
prediction_expiry | string | Expiry date (e.g., "20260331-0300") |
prediction_target_price | number | Target price (price binaries) |
prediction_period | string | Time period (e.g., "1d") |
Admin actions (8 types)
These are emitted when prediction markets are created, modified, or settled by the protocol:
| Type | Description |
|---|
registerQuestion | Register a new prediction question |
registerOutcome | Register a new outcome |
registerNamedOutcome | Register a named outcome |
registerOutcomeToken | Register an outcome token |
registerTokensAndStandaloneOutcome | Register tokens and standalone outcome |
settleOutcome | Settle a prediction market (resolve the outcome) |
changeOutcomeDescription | Update an outcome’s description |
changeQuestionDescription | Update a question’s description |
Subscribing to prediction markets
All user prediction market activity:
{
"action": "subscribe",
"filters": {
"action_types": [
"userOutcome", "splitOutcome", "mergeOutcome",
"mergeQuestion", "negateOutcome"
]
}
}
{
"action": "subscribe",
"filters": {
"action_types": [
"userOutcome", "splitOutcome", "mergeOutcome",
"mergeQuestion", "negateOutcome",
"registerQuestion", "registerOutcome", "settleOutcome"
]
}
}
{
"action": "subscribe",
"filters": {
"asset_ids": [1900001]
}
}