Definition
A mark price is the valuation price a platform uses to calculate open-position value, unrealized P&L, margin, or liquidation conditions.
In market context
The mark may use a bid, ask, midpoint, index, last trade, or methodology designed to reduce the effect of isolated prints. It can therefore differ from the chart’s last price and from the price obtainable for an immediate close. Users should understand the platform’s mark source and update timing because it directly affects displayed equity and account-health calculations at that moment.
Risk context
A valuation mark is not a guaranteed executable price, particularly when a market is closed, volatile, or illiquid.
Source
Use the primary source for fuller regulatory or market context.
