CoinTR futures employs the system called Fair Price Marking to avoid unnecessary liquidations in its highly leveraged products. Under circumstances that the market occurs unnecessary liquidations due to manipulation or lack of liquidity, the fair price marking will not swing with the last price, also won’t cause unnecessary deviations from the index price. Therefore to avoid unnecessary premature liquidation.
For Perpetual Contract, the fair price is equal to the underlying index price plus a decaying funding basis rate.
Price Index is used to check if there’s forced liquidation. It is not used to calculate unrealised profits and losses. (Note that when you make an order, there immediately shows the unrealised profit and loss. It happens when the fair price is slightly different from the last price. This is normal and does not mean you may have lost money, but be sure to keep an eye on your Liquidation Price and Fair Price to avoid a premature liquidation).