Notional loss
Risk & psychologyAlso called: Notional profit, Paper loss, Unrealised loss
An unrealised fall in the value of a holding you still own — real in every sense except that no sale has crystallised it for tax.
In plain terms
The phrase is used to make a fall feel provisional, by people who in the same conversation describe a gain as booked. One rule applied in whichever direction is more comfortable.