Perpetual mechanics

Margin and leverage

Position size equals collateral multiplied by leverage, up to 50x. Maintenance margin is 0.8% of notional; positions falling below it are eligible for liquidation.

positionSize = collateral * leverage
liqPrice(long)  = entry * (1 - 0.92 / leverage)
liqPrice(short) = entry * (1 + 0.92 / leverage)

Mark price

Mark price is a time-weighted composite of the index price and the protocol's own order flow. Using mark price rather than last trade protects positions from wick-driven liquidations.

Liquidations

Liquidations are partial where possible: the engine reduces the position until margin is restored. Remaining collateral is returned to the trader, and a share of the liquidation fee flows to the vault.