Margin is the amount of funds an investor must deposit with an exchange to open a position for perpetual trading. This amount serves as collateral for the exchange against potential investor losses.
Open order margin is the amount held for open orders that have not yet been executed. In other words, if you place a limit, a portion of your margin will be allocated to that order until it is filled or canceled. For example, to place a $1,000 order on a 20% initial margin (5x leverage), the margin requirement is $200.
Maintenance margin is the amount of margin balance required in your account wallet to keep positions open. You will be liquidated if your margin balance falls below the maintenance margin. For example, to maintain a position of $1,000 with a 5% maintenance margin requirement, the margin that will be locked is $50.
Available margin is the portion of your margin balance that is not used for maintenance or open order margins. Available margin can be used to open new positions.
Please note that the maintenance margin may vary for each leverage level. For more information, check the FAQ at this link.