> ## Documentation Index
> Fetch the complete documentation index at: https://docs.roxom.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Mark Price & P&L Settlement

> Margin calculations use Mark Price to prevent manipulation, with P&L realized upon position closure.

### Mark Price for margining

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 won't immediately affect margin calculations *(see*[ *Fair Mark Pricing*](../risk-controls/pre-trade-order-controls) *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, or partially close the position to reduce notional.