As market manipulation will trigger a liquidation chain-reaction, which may inflict unnecessary losses on users. 58COIN tethers to market price by tethering to index price. All PNL are dominated in fair underlying price instead of platform price.
Fair Mark Price: Fair Mark Price = Index Price * (1 + Funding Basis)
For the calculation of Funding Basis, please refer to tether to spot price
Transaction will be executed at the platform price. (The process of opening and closing the position, execution price will be generated only by trading with the counterparty on the platform.)
Marking for Unrealised PNL purpose is done according to the fair underlying price, so you can see your profit and loss immediately after opening a position (this is the result of a fair underlying price calculation). Since the liquidation is calculated at the fair underlying price (mark price), regardless of the volatile internal price of the platform, your Unrealised PNL will not change provided the mark price remains unchanged. This is to avoid “being liquidated”.
For example, currently, the platform price of BTCUSD contract is 7,000. The fair underlying price is 7,005. You can only trade with 7,000 when opening a position, but your Unrealised PNL will be calculated according to 7,005.
If the platform price changes to 6,000 for some reason, the fair underlying price remains 7,005 (there is no change), then your Unrealised PNL is still calculated according to 7,005, and will not be affected by the platform price change. However, if you close the position at this time, your execution price will be 6,000, because the price during the transaction must be generated with the real counterparty.