> For the complete documentation index, see [llms.txt](https://sodex.com/documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sodex.com/documentation/trading-mechanics/contract-specifications.md).

# Contract Specifications

SoDEX Perpetual Futures are **derivative instruments** that are not subject to an expiration or delivery date. Price alignment with the underlying spot market is maintained through a **funding mechanism**, where payments are exchanged between long and short position holders on a periodic basis. (Refer to the Funding section for details.)

### **Margining and Settlement Model**

SoDEX utilizes a **USDC-margined, USDT-denominated linear contract** model.

* **Collateral & Settlement:** The collateral (margin) is held in **USDC**, while the oracle price feed and the Notional Value of the contract are denominated in **USDT**.
* **Quanto Structure:** This configuration means that Profits and Losses (PnL) denominated in USDT are settled and paid out in USDC, classifying these instruments as **Quanto Contracts**. Critically, **no currency conversion is applied** for PnL settlement.
* **Price Feed Exception:** For assets where primary spot market liquidity dictates, the oracle price may be denominated in **USDC**. This is determined on a case-by-case basis using the most liquid oracle sources available.

The SoDEX framework is designed for clarity, featuring a simplified contract specification with minimal asset exceptions and no address-level restrictions.\
**Specification Summary**

| Specification               | Value                                                                                                                       |
| --------------------------- | --------------------------------------------------------------------------------------------------------------------------- |
| Instrument Type             | Linear Perpetual                                                                                                            |
| Contract Size               | 1 unit of the underlying spot asset                                                                                         |
| Underlying Asset / Ticker   | SoDEX oracle index of the underlying spot asset                                                                             |
| Initial Margin Fraction     | 1 / (Leverage set by the user)                                                                                              |
| Maintenance Margin Fraction | 50% of the Initial Margin Fraction                                                                                          |
| Mark Price                  | See [Price Indexes](https://nkhxy47v6o.sg.larksuite.com/wiki/AymIwMzDGi9YeKkdDe8lA3c1glh#share-QdWXduGfHoMbnHxMypflgeO7gmm) |
| Delivery / Expiration       | Not Applicable (Funding payments occur every hour)                                                                          |
| Position Limit              | Not Applicable                                                                                                              |
| Account Type                | Per-wallet cross or isolated margin                                                                                         |
| Funding Impact Notional     | 200 USD \* Max Leverage of the specific asset                                                                               |
| Maximum Market Order Value  | <p>Varies by asset:</p><ul><li>BTC, ETH: $4,000,000</li><li>Other Assets: $1,000,000 - $2,000,000</li></ul>                 |
| Maximum Limit Order Value   | Same as the Maximum Market Order Value for the specific asset                                                               |