All margin calculations (initial requirements, maintenance, unrealized P&L) use the Mark Price rather than the 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 wonât immediately affect margin calculations (seeFair Mark Pricingfor a detailed view on the implementation).
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 positionâs margin ratio safe). Traders may manually add or remove margin to a position (as long as it stays above initial requirements) to manage risk, or partially close the position to reduce notional.