Margin
Isolated and cross margin, leverage, and switching between them.
Each market has its own margin mode, isolated by default.
Isolated
The margin for a position is its own bucket. If the position goes wrong, it can only lose that bucket. The rest of your balance is untouched.
Cross
Positions share your balance as margin. Profit on one position supports another. If your shared balance falls below their combined maintenance margin, they are liquidated one at a time, largest first, until the account is healthy again.
Leverage
You set leverage per market, up to the market's maximum, and can change it while a position is open. See Contract specifications.
Switching modes
You can switch a market between isolated and cross when you have no position and no open orders in it, and not while a liquidation is in progress.