The collateral is the amount of funds blocked in the user's margin account when placing an order or increasing the net position. This is the insurance that guarantees the fulfilment of their obligations by the trader.
Calculation of the standard collateral for perpetuals:
Sm – Standard collateral
– Net position size
mP – Mark price
Cc – Collateral ratio. It varies for different assets, for BTC it equals 0,1.
Collateral in absolute terms is a dynamic parameter, since the price can change.