> ## Documentation Index
> Fetch the complete documentation index at: https://dexbuilder.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Fees

> Understand Event Contracts trading-fee calculations, fee-rate structure, and precision rules.

Event Contracts 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:

```text theme={null}
fee = C × feeRate × p × (1 - p)
```

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

| Market Category | Maker / Taker Fee Rate |
| - | -: |
| Crypto | `0.07` |
| Sports | `0.05` |
| Finance | `0.04` |
| Politics | `0.04` |
| Economics | `0.05` |
| Culture | `0.05` |
| Weather | `0.05` |
| Other / General | `0.05` |
| Mentions | `0.04` |
| Tech | `0.04` |
| Geopolitics | `0` |

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

## Precision

Fee amounts are kept to 5 decimal places. The minimum fee precision is:

```text theme={null}
0.00001 USDT
```

Fees below the minimum precision may round to `0`.

> [!NOTE]
>
> 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.


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