> ## 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

- [Portfolio Margin Parameters](/untitled-page-3.md)
- [Standard Margin Parameters](/untitled-page-2.md)
- [Trading Fees on Derive: Maker, Taker, RFQ, and Liquidation](/integrators/trading/trading-fees.md)