Three prices, three jobs
| Price | What it is | Used for |
|---|---|---|
| Index price | A volume-weighted average from major spot exchanges, with safeguards against outliers. | The reference value of the asset. |
| Mark price | A fair price derived from the index, the order book and the funding rate. | Unrealized PnL, margin and liquidation. |
| Last price | The price of the most recent trade on AtlasPerp. | Display only, never liquidation. |
How PnL is calculated
Formulas
Unrealized PnL = position size × (mark price − average entry price)
Realized PnL = closed size × (exit price − average entry price)
Position value (notional) = position size × mark price
For short positions the size is negative, so a falling price produces a profit. Trading fees are charged in USDC on every fill and are included in your average entry price.
Settling PnL
Realized profit and loss is first recorded as unsettled. Settling moves it into your balance so that it can be withdrawn. It does not change your positions or your margin ratio. Select Settle PnL in Portfolio before withdrawing profits.
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