Cross-margin is a margin trading configuration where a trader’s entire account balance acts as shared collateral for all open positions simultaneously — meaning unrealized profits from a winning trade automatically support a losing trade’s margin requirement, reducing the risk of liquidation from any single position while also meaning that a catastrophic loss on one position can deplete funds allocated to every other position in the account. Cross-margin is the default mode on most centralized and decentralized derivatives exchanges. It maximizes capital efficiency by pooling collateral, allowing traders to hold more positions without explicitly allocating collateral to each one, but it creates systemic risk within the account: one bad position threatens everything.
How Cross-Margin Works
Shared Collateral Pool
In cross-margin mode, the account’s margin balance is undivided:
“`
Account Balance: 10,000 USDC (total collateral for ALL positions)
Position A: Long ETH $50,000 notional — currently +$1,200 profit
Position B: Long BTC $30,000 notional — currently -$800 loss
Position C: Short SOL $10,000 notional — currently +$300 profit
Available margin: 10,000 + 1,200 – 800 + 300 = 10,700 USDC effective
“`
Position B’s loss is automatically offset by the profits from A and C. The account is not liquidated until the total margin falls below the maintenance margin requirement across all positions combined.
Liquidation in Cross-Margin
Liquidation occurs when the combined margin across all positions falls below the maintenance margin threshold. The exchange may liquidate the position causing the most immediate stress — or liquidate all positions simultaneously — to restore solvency.
Example scenario:
- Account: 1,000 USDC
- Open: Long ETH at $3,000 with 10x leverage ($10,000 notional)
- Maintenance margin: 0.5% = $50
- ETH drops to $2,955 → position loss = $150 → margin = $850 → still OK
- ETH drops to $2,500 → position loss = $500 → margin = $500 → still OK
- ETH drops to $2,050 → position loss = $950 → margin = $50 → liquidation trigger
In cross-margin, that single $50 is the buffer protecting the entire account.
Cross-Margin vs. Isolated Margin
| Feature | Cross-Margin | Isolated Margin |
|---|---|---|
| Collateral scope | Entire account balance | Only what you assign to that position |
| Liquidation risk | Account-wide; one loss affects all | Position-specific; isolated losses |
| Capital efficiency | High — shared pool reduces idle capital | Lower — must explicitly fund each position |
| Risk management | Harder — must monitor entire account | Easier — per-position risk is capped |
| Typical use | Professionals managing many positions | Degens making high-leverage single bets |
| Liquidation price | Moves as account balance changes | Fixed at open (based on allocated margin) |
Cross-Margin on Decentralized Perpetuals
dYdX (v3 / v4)
GMX
Hyperliquid
Portfolio Margin (Advanced Cross-Margin)
Professional derivatives exchanges (dYdX Unlimited, Vertex) implement portfolio margin — an extension of cross-margin that:
- Accounts for correlation between positions (long ETH + short BTC may partially hedge each other)
- Reduces total margin requirement below naive cross-margin calculation
- Allows lower margin ratios for well-hedged portfolios
- Requires more sophisticated real-time risk calculation
Portfolio margin is standard in TradFi prime brokerage and is increasingly available in DeFi perpetuals.
Risk Management in Cross-Margin
Best Practices
Set stop-losses on every position: Without stops, a single runaway loss can drain the entire account.
Monitor effective leverage: In cross-margin, your total notional exposure / account balance = effective leverage. This number increases as losing positions grow.
Don’t over-concentrate: If 80% of your account is in one position, cross-margin provides little benefit vs. isolated. Diversification is where cross-margin actually helps.
Watch funding rates: In cross-margin, a position with very negative funding rate is continuously draining the shared margin pool even without price movement.