Currently Poloniex perpetual contract supports isolated mode, meaning each contract has a separate margin account. Margin, margin percentage and P&L of all contracts are calculated separately and won’t affect each other.

Initial Margin 

Initial Margin is the minimum amount when traders open a position, also called Cost.

Initial Margin = order value * Initial Margin percentage + taker fee for opening position + taker fee for closing position

Actual fee will be charged when order executes, and based on the executed price. If traders place order to close position, no margin is charged.

Maintenance Margin

Maintenance Margin is the minimum amount to hold the position.

Maintenancel margin = order value * Maintenance Margin percentage + taker fee for closing the position

When margin balance falls below the margin requirement, the position will be liquidated. Normally Maintenance Margin is half of the Initial Margin.

For example, if a trader uses 100x leverage to long 5 BTC at 5000 USDT, it requires 0.05 BTC (fees not included) as margin to open the position. If the price of the contract goes up by 1%, the trader will profit 100 times of the margin. Through the usage of margin and leverage, the trader gained a higher rate of return with less funds.

But if the price of the contract falls by 0.5% and the position is in Isolated Margin mode, the position will be liquidated and all the margins will be lost. However, the maximum loss is limited to the funds used for margin.

Traders could check the Initial Margin percentage and Maintenance Margin percentage at Contract Specifications.