Cross-Margin (Portfolio Margin)

Cross-margin (also called portfolio margin) lets every open position share the same collateral. You do not set aside separate margin for each trade.

That can use capital more efficiently. A gain in one position may help cover a loss in another. The tradeoff is shared risk: a bad move can draw down collateral backing every position. In the worst case, one account-wide liquidation can close several trades at once.

Example: if two positions share $1,000 of collateral, the platform may use the whole $1,000 to cover losses. With isolated margin, each position has its own limit.

Isolated margin is the alternative. Each position risks only its own collateral, so liquidation of one position does not directly close another. It is easier to reason about, but unused collateral cannot help another position.

Whether a platform offers cross-margin, isolated margin, or both is a real, concrete thing to check before opening more than one position on it — see our Perpetuals category page for how this factors into evaluating a perps venue, and our onchain options guide for how portfolio margin specifically shows up in venues like Derive, which markets cross-margin support as a core feature of its CLOB.