P&L (Unrealized Profit/Loss)
Unrealized Profit/Loss represents an increase/decrease in the value of an open position. Unrealized P&L is a reflection of what profit or loss could be realized if the position were closed at that specific time. P&L does not become realized until the position is actually closed.
P&L is calculated as the difference between the Current Price and the Open Price of an asset multiplied by the Position Size.
FPL = (Current Price - Open Price) * Position Size
For example, you open a Long Position for 1 BTC at the BTC price of $9,000. If the next day BTC price is $9,100, your unrealized gain is $100.
The price may also take a nosedive and drop to $8,500 by the end of the day. Since your position remained open, you are now in for $500 loss ($9,000 - $8,500).
Yet still, the loss is not your final verdict unless you actually close your position. If in two days BTC price recovers to $9,050 and you close the position, you finally turn your unrealized gain into realized $50.