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

# Common Parameters

| Parameter | Value | Description |
| - | - | - |
| MAX\_EXPIRY | 400 days | The longest dated option that can be listed. |
| SETTLEMENT\_TWAP\_PERIOD | 30 minutes | Options settle to a TWAP of the market's base asset price over this window. The published settlement divides the aggregated feed by the **actual** seconds aggregated, not by 1,800. |
| FEED\_HEARTBEAT | 3,600 s | Maximum age of a spot, perp, vol, rate or forward feed print. |
| CONFIDENCE\_THRESHOLD | 0.55 | Feed confidence beneath which extra initial margin applies, in both engines. |
| CONFIDENCE\_SCALE (PM) | 0.4 | Percentage of spot added per contingent contract by the PM oracle contingency. |
| CONFIDENCE\_SCALE (SM) | 1.0 | As above, for Standard Margin. |
| (MIN\_SCALE, MAX\_SCALE) | (4, 4) | Moneyness clamp on the SVI smile: `k` is clamped to `± SCALE x sqrt(a + b x sigma)`. |
| MAX\_TOTAL\_VOL | 24.0 | Cap on total volatility read off the surface. |
| MAX\_TOTAL\_VAR | 144.0 | Cap on total variance read off the surface. |


## Related topics

- [Liquidation Parameters](/liquidation-parameters.md)
- [Portfolio Margin Parameters](/portfolio-margin-parameters.md)
- [Standard Margin Parameters](/standard-margin-parameters.md)


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