For a SHORT position:

$\text{Unrealized P\&L} = \text{Quantity} \times (\text{Average Entry Price} – \text{Best Ask Price})$

Unrealized P&L=Quantity×(Average Entry Price−Best Ask Price) Where:

• Quantity: Amount of contracts or units held.
• Average Entry Price: Average price at which the position was entered.
• Best Ask Price: Current lowest price at which sellers are willing to sell the asset.

Example:

Assuming a Trader enters into a long position of 0.1 BTCUSDT perpetual swap contracts at an average entry price of 30,000 USDT:

1. If the Best Bid Price moves to 36,000 USDT:
   $\text{Unrealized P\&L} = 0.1 \text{ BTC} \times (36,000 – 30,000) \text{ USDT} = 600 \text{ USDT}$ 

   $\text{Unrealized P\&L}=0.1\text{ BTC}\times (36,000-30,000)\text{ USDT}=600\text{ USDT}$

2. If the Best Bid Price moves to 24,000 USDT:
   $\text{Unrealized P\&L} = 0.1 \text{ BTC} \times (24,000 – 30,000) \text{ USDT} = -600 \text{ USDT}$ 

   $\text{Unrealized P\&L}=0.1\text{ BTC}\times (24,000-30,000)\text{ USDT}=-600\text{ USDT}$