What Is Isolated Margin? Per-Position Risk Control Explained
Isolated margin is a margin mode in perpetual futures trading where each position is assigned its own dedicated pool of collateral. If the trade goes against you and hits liquidation, you lose only the margin allocated to that specific position. Your remaining account balance and any other open positions are completely unaffected. On Perpmate, isolated margin gives you granular control over how much USDC you put at risk on each individual trade.
How Isolated Margin Works
When you open a position in isolated margin mode, you explicitly choose how much margin to assign. That amount becomes the maximum you can lose on the trade, regardless of how far the price moves against you.
Here is the step-by-step flow:
- You have 5,000 USDC in your Perpmate account.
- You open a 20x long on ETH and allocate 500 USDC as isolated margin.
- Your position size is 500 x 20 = 10,000 USDC.
- If ETH drops far enough to deplete your 500 USDC margin, the position is liquidated.
- You lose the 500 USDC. Your remaining 4,500 USDC is safe and untouched.
This containment is the defining advantage of isolated margin. Each trade is a self-contained bet with a known maximum loss.
Isolated Margin vs Cross Margin
The choice between isolated and cross margin comes down to how you want to distribute risk.
| Feature | Isolated Margin | Cross Margin |
|---|---|---|
| Risk per trade | Capped at allocated margin | Extends to entire balance |
| Liquidation buffer | Only the assigned margin | Full account balance |
| Capital efficiency | Lower (funds locked per position) | Higher (shared pool) |
| Position independence | Full (positions do not affect each other) | None (all positions share collateral) |
| Adding margin | Manual (you decide when and how much) | Automatic (free balance absorbed) |
Practical Example: Managing Two Trades
Imagine you have 3,000 USDC and want to open two positions:
Trade 1 -- Long BTC at 10x
- Isolated margin allocated: 1,000 USDC
- Position size: 10,000 USDC
- Approximate liquidation: ~10% drop from entry
Trade 2 -- Long SOL at 20x
- Isolated margin allocated: 500 USDC
- Position size: 10,000 USDC
- Approximate liquidation: ~5% drop from entry
Scenario: SOL crashes 8%. Your SOL position is liquidated and you lose the 500 USDC allocated to it. But your BTC position is completely unaffected, and you still have 1,500 USDC in free balance. Total damage: 500 USDC, not your entire account.
Under cross margin, the SOL loss would have drawn from your free balance and potentially dragged your BTC position closer to liquidation as well.
Liquidation Price in Isolated Margin
Your liquidation price in isolated margin is determined solely by the margin you assign and your leverage. The less margin you allocate, the closer your liquidation price sits to your entry.
| Allocated Margin | Leverage | Position Size | Approx. Liquidation Distance |
|---|---|---|---|
| 250 USDC | 40x | 10,000 USDC | ~2.5% |
| 500 USDC | 20x | 10,000 USDC | ~5% |
| 1,000 USDC | 10x | 10,000 USDC | ~10% |
| 2,000 USDC | 5x | 10,000 USDC | ~20% |
If you open a 10,000 USDC position at 40x leverage with only 250 USDC margin, a mere 2.5% adverse move liquidates you. At 5x with 2,000 USDC margin, you can withstand roughly a 20% move. The tradeoff is clear: more margin means more room, but also more capital locked up in a single trade.
Adding Margin to an Open Position
One powerful feature of isolated margin is the ability to add margin after the fact. If a trade is moving against you but you still believe in the thesis, you can deposit additional USDC to that position:
- Your long BTC position has 500 USDC margin and is approaching liquidation.
- You add 300 USDC from your free balance, bringing the total isolated margin to 800 USDC.
- Your liquidation price moves further away, giving the trade more breathing room.
This is a deliberate decision, unlike cross margin where your free balance is consumed automatically. You control exactly when and how much additional risk to take.
When to Use Isolated Margin
Isolated margin is the right choice in several common scenarios:
High-Leverage Speculative Trades
When you want to take a 20x or 40x shot on a breakout or news event, isolated margin caps your downside. You can risk 200 USDC on a high-conviction trade without exposing the other 4,800 USDC in your account.
Uncorrelated Positions
If you are trading multiple assets that move independently (BTC and a low-cap altcoin, for example), isolated margin prevents one asset's crash from cascading into your other positions.
Learning and Experimentation
New to perpetual futures? Start with isolated margin. It forces you to define your risk upfront and teaches discipline. You cannot accidentally blow your account on a single trade.
Best Practices for Isolated Margin
- Define your risk before entering: Decide the maximum USDC you are willing to lose and set that as your isolated margin.
- Pair with stop-losses: Even though isolated margin caps your loss, a stop-loss (TL) can exit the trade before liquidation, saving a portion of your margin.
- Do not over-allocate: If you put 90% of your balance into one isolated position, you have effectively created a cross-margin-like risk profile.
- Set take profit targets: Use TP orders to lock in gains automatically, ensuring winners are realized.
- Monitor funding costs: Funding rate payments come out of your isolated margin. If funding is high and your margin is thin, it can accelerate liquidation.
For a complete comparison of isolated vs. cross margin with worked examples, see Cross Margining in Crypto.
Related Terms
- Margin: The collateral required to open and maintain leveraged positions
- Cross Margin: The alternative mode where your full balance backs all positions
- Liquidation Price: The price at which your isolated margin is depleted
- Leverage: Determines position size relative to your allocated margin
- PnL: Profit and loss within the bounds of your isolated margin