> For the complete documentation index, see [llms.txt](https://docs.carbondefi.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.carbondefi.xyz/contracts-and-functions/carboncontroller-functions/data-and-events/tradingfeeppmupdated.md).

# TradingFeePPMUpdated()

{% code title="CarbonController.sol" overflow="wrap" lineNumbers="true" %}

```solidity
    event TradingFeePPMUpdated(uint32 prevFeePPM, uint32 newFeePPM);
```

{% endcode %}

This event indicates when the trading fee, in parts-per-million, is updated. 

### Event Parameters

| Name       | Type   | Description              |
| ---------- | ------ | ------------------------ |
| prevFeePPM | uint32 | The previous trading fee |
| newFeePPM  | uint32 | The new trading fee      |