Margining (Legacy)

Margin calculations closely mirror the formulas utilized by centralized derivatives exchanges.

Margin Mode

When opening a position, a margin mode must be selected. Cross margin (default) utilizes shared collateral across all cross-margin positions for maximum capital efficiency. An isolated margin restricts collateral allocation to the specific asset, ensuring liquidation:

• In isolated positions, the margin doesn't affect cross/other isolated positions.

• In cross/other isolated positions, the margin doesn't affect this isolated position

• Isolated margin only supports USDC as collateral, and PNL can be offset within positions using the same asset.

• Cross margin supports multiple assets (USDC, BTC, ETH) as collateral, and PNL can be offset across them.

Initial Margin and Leverage

Users may select leverage as any integer between 1 and the asset-specific maximum leverage. Position margin requirements are calculated as: Initial Margin = Position Size × Mark Price ÷ Leverage

• Cross Margin:

  • Initial margin is locked and non-withdrawable

  • Unrealized PNL automatically serves as available margin for new positions

• Isolated Margin:

  • Supports post-opening margin adjustments (add/remove)

  • Unrealized PNL applies as an additional margin to the open position

Unrealized PNL and transfer margin

Unrealized PNL withdrawal from isolated positions or cross accounts follows the following formulas:

• initialMargin = entryPrice * positionSize / leverage

• floatingMargin = isolatedMargin - initialMargin

• floatingProfit = calculateFloatingProfitAndLoss(...)

• availableSubtractMargin = max(0, min(floatingMargin, floatingMargin + floatingProfit))

'Transfer' encompasses any non-trading margin removal, including:

• External withdrawals

• Transfers to spot wallets

• Isolated margin position transfers

Maintenance Margin & Liquidation Mechanics

Cross positions trigger liquidation when: Account Value (incl. unrealized PNL) < Maintenance Margin × Total Open Notional PositionMaintenance Margin = Position value * mainMarginRateThe value of mainMarginRate in various symbols is different. For example, when you open a position below maxNominalValue of 12,500,000 USDC under BTC_USDC, then the mainMarginRate is 0.004. The current Maintenance Margin Rate (mainMarginRate) on SoDEX Testnet for different symbols is consistent, as follows (Updated on 2025.08.01):

Bracket	Max Nominal Value (USDC)	Maint Margin Rate	Start Margin Rate	Max Leverage	Min Leverage
1	10,000,000	0.30%	0.50%	200x	1x
2	12,500,000	0.40%	0.80%	125x	1x
3	20,000,000	0.50%	1.00%	100x	1x
4	25,000,000	1.00%	2.00%	50x	1x
5	50,000,000	2.50%	5.00%	20x	1x
6	100,000,000	5.00%	10.00%	10x	1x
7	200,000,000	10.00%	20.00%	5x	1x
8	400,000,000	12.50%	25.00%	4x	1x
9	1,500,000,000	15.00%	33.30%	3x	1x
10	2,000,000,000	25.00%	50.00%	2x	1x
11	5,000,000,000	50.00%	100.00%	1x	1x

Isolated positions follow identical liquidation logic, with computation inputs solely comprising:

• Isolated margin balance

• The isolated position's notional value