Mark Price

Mark price is the reference valuation a derivatives exchange uses to calculate unrealised profit and loss and to decide when a leveraged position is liquidated. Rather than the last traded price on its own book — which a single large order or thin liquidity can move briefly — it is usually derived from an index of spot prices across several venues, sometimes adjusted for funding. The separation matters twice: it makes a position harder to liquidate by manipulating one market, and it explains why a position can survive a wick on the chart that appears to have crossed the liquidation level.