On CoinFLEX all derivative contracts (Perps, Futures, Spreads, Rate Index Futures) are denominated in USD. Therefore P&L and margin is posted in USD in users accounts and collateral is also measured in USD terms. USD is fungible with USDC so for all intents and purposes CoinFLEX refers to USDC as USD.
By default all coin balances in a single sub-account are aggregated together to be counted as collateral in USD terms. Each user’s sub-account has isolated margin and therefore collateral from all other sub-accounts. This means that users can only lose collateral from a trade(s) limited to the sub-account itself from which the trade(s) originated from.
Since all coin balances in a sub-account contribute towards collateral for that sub-account, an LTV factor is applied to each coin balance before its USD collateral value is determined. The table below shows the LTV factors for all the coins which are accepted as collateral on CoinFLEX.