Traders can deposit any SPL token supported by Jupiter Swap as the initial margin to open a position or to deposit collateral for an existing open position.
The deposited tokens will then be converted to the collateral tokens for the position (SOL / ETH / wBTC for long positions, USDC for short positions).
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.
The underlying collateral for long positions are the tokens themselves (SOL, wBTC, ETH) and stablecoin (USDC) for short positions.
This is to protect the pool from scenarios that might put the pool at risk, for example a series of ongoing profitable trades that deplete the pool's reserves.