TradFi Perps on BitMEX are quoted against USDT, and their settlement currency is also USDT. All realised and unrealised profit and loss (PnL) is denominated in USDT. This means traders always know exactly how much they have gained or lost in stablecoin terms, regardless of the underlying stock, forex, or commodity.
What is unrealised PnL?
Unrealised PnL reflects the current gain or loss on an open position. It changes in real time as the mark price moves. The formula for a long position is:
Unrealised PnL = (Mark Price - Entry Price) x Quantity
For a short position, the formula reverses:
Unrealised PnL = (Entry Price - Mark Price) x Quantity
Unrealised PnL becomes realised PnL once the position is closed.
What is realised PnL?
Realised PnL is the final profit or loss recorded when a position is partially or fully closed. It also includes funding payments and trading fees. The formula is:
Realised PnL = (Exit Price - Entry Price) x Quantity - Fees +/- Funding
All values are calculated and settled in USDT.
Understanding the PnL formulas helps traders evaluate position performance accurately.
Why does USDT settlement matter?
Three practical benefits apply:
- Predictable PnL: Profits and losses are in USDT, a stablecoin pegged to the US dollar. No currency conversion risk.
- Unified margin: Traders use USDT across all equity perps positions, simplifying portfolio management.
- Consistency across contracts: Whether trading AAPLor SPY equity perps or USD/JPY forex perps, the settlement currency remains USDT.
How do funding payments affect PnL?
Funding payments are exchanged between long and short holders periodically. These payments are added to or deducted from realised PnL. A trader holding a long position when the funding rate is positive pays the funding fee. When the rate is negative, the long holder receives the payment.
Funding costs can accumulate over time and should be factored into overall PnL calculations.