​
Mark Price for Margining

All margin calculations (initial requirements, maintenance, unrealized P&L) use the Mark Price rather last traded price. This is a critical risk management practice to avoid unjust liquidations or margin calls due to momentary trading anomalies. By basing margin on the fair Mark Price (which is a blended index price), sudden spikes or manipulation of the traded price won’t immediately affect margin calculations (see Fair Mark Pricing for a detailed view on the implementation).

​
Margin and P&L Settlement

Profits and losses on open positions accrue in real-time to your account equity (unrealized P&L). However, in isolated mode, you cannot withdraw unrealized profits until the position is closed (since that P&L is keeping the position’s margin ratio safe). Traders may manually add or remove margin to a position (as long as it stays above initial requirements) to manage risk, as long as partially close the position to reduce notional.