Mark price

Subscribe to mark price updates for a single symbol via WebSocket, pushed every second.

Push interval: 1s

{
  "id": "clientID8",
  "topic": "PERP_ETH_USDC@markprice",
  "event": "subscribe"
}

Parameters

Name	Type	Required	Description
id	string	Y	id generate by client
event	string	Y	subscribe/unsubscribe
topic	string	Y	{symbol}@markprice

Response

{
  "id": "clientID8",
  "event": "subscribe",
  "success": true,
  "ts": 1682241795883
}

Subscribed Message

{
  "topic": "PERP_ETH_USDC@markprice",
  "ts": 1682241796000,
  "data": {
    "symbol": "PERP_ETH_USDC",
    "price": 2300.0
  }
}

Orderly Predict

For a Predict round symbol (<binary_symbol>), markprice uses the existing topic and payload with no added fields. During trading, the mark price equals the round’s own index price — see Underlying price data for how that index price is derived. At expiry it ends at exactly 0, 0.5, or 1.