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Prediction Markets fees are calculated per fill. The effective rate can vary by market category and business configuration.

Fee Calculation

Under the dynamic-fee model, fees can be calculated using:
Where:
  • C: number of shares filled;
  • feeRate: fee parameter for the relevant market category;
  • p: execution price of the outcome share.
Because the formula contains p × (1 - p), the fee is higher when the price is close to 0.5 and gradually decreases as the price approaches 0 or 1.

Default Category Fee Rates

The effective fee rate is determined by the value returned by the relevant market API or account fee API.

Symmetry

The dynamic fee is symmetric around a 50% probability. Under otherwise identical conditions, trades executed at 0.30 and 0.70 incur the same fee amount.

Precision

Fee amounts are kept to 5 decimal places. The minimum fee precision is:
Fees below the minimum precision may round to 0.
The actual Builder or Broker fee structure may be configured according to the business partnership. Public-facing applications should use the current values returned for the relevant market and account.