When providing the initial margin or depositing collateral, the exchange records the position's collateral value in USD. The recorded USD value remains constant, even if the collateral token's price fluctuates.
For example, if a trader deposits $100 USD worth of SOL to open a position, their collateral will always be valued at $100 for this position. Even if the price of SOL changes by 50% in either direction, the trader's collateral size for this position remains fixed at $100.
The platform will automatically swap the deposited tokens to the right collateral token so traders don't need to swap tokens manually before opening a position or increasing their collateral.