Maintenance Margin is the minimum margin required to continue holding a position.
It will increase or decrease depending on the trader's trading volume. Liquidation occurs when the isolated margin for the position is less than its maintenance margin level.
Trader place a long position of 1 BTC at VNDC 200,000,000 with 50x leverage (Isolated Margin)
Initial Margin = (1 * 200000000) / 50 = 4,000,000 VNDC
Maintenance Margin = 1 * 200000000 * 0.1% = 200,000 VNDC
This means that this position could take an unrealized loss (Mark Price) of up to 3,800,000 VNDC (4,000,000 VNDC – 200,000 VNDC) before liquidation takes place.