Margin is the collateral that backs a leveraged position. How that collateral is allocated, walled off per position (isolated margin), shared across your whole account (cross margin), or measured against your portfolio's net risk (portfolio margin), changes how much you can trade, how long a position survives a drawdown, and how much you stand to lose. This guide explains all three and how unified margin ties them together.
This is article nine in our series on crypto options trading. The previous articles covered individual trades; this one covers the account-level machinery that makes those trades capital efficient. If you are new to derivatives, start with what crypto options actually are first.
TL;DR
Isolated margin walls off a fixed amount of collateral per position. Maximum loss on that trade is the margin you assigned. Nothing else in your account is at risk
Cross margin shares your entire account balance across all positions. More capital efficient and resists liquidation longer, but a severe loss can draw on your whole balance
Portfolio margin is risk-based: collateral is set by the net risk of your whole book, so hedged positions require less. It originated in traditional finance; crypto's version is unified cross-margin
Unified margin on Paradex lets one USDC account back options, perpetuals, and spot together, so gains on one position support margin on another
All margin trading carries liquidation risk. Leverage amplifies losses as well as gains. Neither mode removes that risk; they distribute it differently
What is cross margin?
Cross margin is a mode where all the collateral in your account backs all of your open positions at once. Instead of assigning a fixed amount of margin to each trade, your entire account balance acts as a shared buffer. If one position moves against you, the rest of your balance automatically supports it, which means a profitable position can help keep a losing one alive.
The benefit is capital efficiency and staying power. Because the whole account defends each position, a trade can absorb a deeper drawdown before it is liquidated. The cost is that the risk is shared too: a severe loss on one position can draw down funds that were supporting your other trades, and in the worst case it can reach your entire balance rather than a walled-off portion.
Cross margin suits traders running hedged or correlated positions, where gains and losses naturally offset, and traders who want to use their capital efficiently across a book rather than locking it into separate buckets.
What is isolated margin?
Isolated margin walls off a fixed amount of collateral for a single position. The most you can lose on that trade is the margin you assigned to it. If the position is liquidated, the loss stops there, and the rest of your account is untouched.
The benefit is containment. Isolated margin turns each position into a sealed compartment, so a single bad trade cannot sink the whole account. The cost is that the position gets no help from the rest of your balance: once its assigned margin is exhausted, it is liquidated, even if you have plenty of idle collateral elsewhere.
Isolated margin suits high-conviction directional bets where you want a hard ceiling on the downside, and any situation where you want to ring-fence the risk of one position from everything else you hold.
Cross margin vs isolated margin: which should you use?
The difference comes down to one question: should your positions share collateral, or each stand alone? Here is the comparison side by side.
Feature
Cross margin
Isolated margin
Collateral
Whole account backs every position
Fixed amount per position
Maximum loss per position
Up to the full account balance
Capped at the assigned margin
Capital efficiency
High: shared collateral, positions offset
Lower: collateral locked per position
Liquidation resistance
Survives deeper drawdowns
Liquidated once assigned margin is gone
Risk containment
One bad move can affect the whole account
Damage sealed to one position
Best for
Hedged or correlated books, capital efficiency
Standalone directional bets, hard risk ceiling
A simple way to see the difference is to watch how the same $10,000 account allocates collateral in each mode.
Same $10,000 account. Isolated walls collateral into per-position buckets; cross pools it so every position is backed by the whole balance.
In the isolated example, the BTC position can lose at most its assigned $2,000 before liquidation, no matter how much idle USDC sits in the account. In the cross example, all $10,000 stands behind every position, so the BTC trade survives a far deeper drawdown, but a catastrophic move could consume collateral that was supporting ETH and SOL too.
What is portfolio margin?
Portfolio margin is a risk-based margining system that sets your collateral requirement from the total risk of your whole portfolio, rather than summing the requirement of each position in isolation. Because offsetting positions reduce net risk, a hedged book under portfolio margin typically requires far less collateral than the same positions margined one by one.
Portfolio margin originated in traditional finance, where it is an account type offered by equities and derivatives brokers to experienced and institutional traders, usually with high minimum balances. It contrasts with Reg T margin, the older fixed, rules-based system that applies a set percentage to each position independently regardless of how positions offset each other.
The distinction matters because crypto's unified cross-margin is the on-chain evolution of the same idea. Where portfolio margin in traditional finance gates risk-based efficiency behind large minimums and a brokerage account, a unified-margin crypto account applies comparable risk-based logic across options, perpetuals, and spot without those minimums. The concept that institutions paid up to access is becoming the default for any self-custodial trader.
The through-line: isolated margin is the most conservative (per-position walls), cross margin shares one pool, and portfolio margin measures net portfolio risk. Each step up the ladder is more capital efficient and requires more care, because the more your positions share collateral, the more they share fate.
How do you choose between cross and isolated margin?
There is no universally correct mode. The right choice depends on what each position is for and how much per-trade risk you want to contain. Here is a practical sequence.
1Define the position's role. A standalone directional bet favours isolated margin, which caps its risk. A position that is part of a hedged or correlated book favours cross margin, which lets the pieces support each other.
2Assess your risk tolerance per position. If you want a hard ceiling on what a single trade can lose, choose isolated and assign only the collateral you are willing to lose. If you want positions to back each other, choose cross.
3Check the collateral and resulting leverage. Review how much collateral backs the position and the leverage that implies. Leverage amplifies losses as well as gains and brings the liquidation price closer to the current price.
4Open the position in your chosen mode. On Paradex, open from your unified USDC account and select cross or isolated. In cross mode the whole account backs the position; in isolated mode you assign a fixed amount.
5Monitor your margin ratio. After opening, track your margin ratio and liquidation price. In cross mode, watch the health of the whole account; in isolated mode, watch the position's assigned margin. Set alerts or stops to manage liquidation risk.
How does unified margin work on Paradex?
Paradex is an on-chain venue for crypto options, perpetual futures, and spot, all from one self-custodial account. Its margin system is unified: a single USDC-denominated account collateralises positions across every market, rather than forcing a separate margin account for each instrument.
Unified margin is where cross-margin efficiency becomes most powerful. Because options, perpetual futures, and spot share one collateral pool:
Unrealised gains support new margin. A profitable ETH position's unrealised PnL can help collateralise a BTC position, so capital is not stranded across separate accounts.
Hedges are recognised. Offsetting positions reduce the collateral the account needs, the same risk-based logic that portfolio margin brought to traditional finance.
A covered call is backed by its own spot. The covered call strategy works naturally here: the BTC you hold collateralises the call you sell against it, in one account.
Multi-leg structures share collateral. Spreads, collars, and straddles draw on the unified pool rather than locking margin per leg.
A few things that differentiate Paradex for margin trading: a flat 0.0075% options fee, capped at 12.5% of the premium for retail accounts (see the trading fees documentation), self-custody throughout, position privacy via ZK technology, settlement on Paradex Chain (StarkNet L2), and institutional liquidity from the team behind Paradigm, the largest institutional options liquidity network in crypto.
For traders in India, Singapore, the UK, Brazil, and other global markets, the experience is identical: connect a wallet, fund a single USDC account, and trade options, perps, and spot under one margin system. For live volume and open interest, see paradex.trade/stats; for the full mechanics of margining and liquidation, the documentation covers it end to end.
See unified margin in action. Open a position on Paradex, choose cross or isolated margin, and watch how one USDC account backs options, perps, and spot together. Connect your wallet to get started.
Margin trading carries real risk, and no choice of margin mode removes it. Understanding the risk before you trade is what separates a deliberate position from an expensive one.
Liquidation is the central risk. If your losses exceed the collateral available to a position, the position is liquidated, closed automatically to prevent further loss. In isolated mode, liquidation costs you the assigned margin. In cross mode, liquidation can draw on your entire account balance, because the whole account was backing the position.
Leverage amplifies both directions. Margin lets you control a larger position than your collateral alone would allow. That magnifies gains, but it magnifies losses by exactly the same factor, and it moves your liquidation price closer to the current price. Higher leverage means a smaller adverse move can wipe out the position.
Cross margin trades containment for staying power. It resists liquidation longer, but the trade-off is that a severe loss is not walled off. Use cross margin where positions genuinely offset, not as a way to keep a losing directional bet alive past the point where you should have closed it.
Risk reminder: Leveraged trading can result in the loss of your entire margin and, in cross mode, your full account balance. Only trade with capital you can afford to lose, monitor your margin ratio actively, and use stops to manage downside. Leverage amplifies losses as well as gains.
What is the one thing to remember?
The more your positions share collateral, the more they share fate. Isolated margin keeps each trade in its own sealed compartment. Cross margin pools your capital for efficiency and staying power. Portfolio margin, and its crypto descendant unified margin, measure the net risk of your whole book and reward positions that offset.
There is no single right answer. Match the mode to the position: isolate the standalone bets you want to ring-fence, cross-margin the hedged book you want to run efficiently, and let unified margin do the work of recognising how your options, perps, and spot fit together. Choose with intention, size with respect for leverage, and watch your margin ratio.
Frequently asked questions
Cross margin is a mode where all the collateral in your account backs all of your open positions at once. Instead of assigning a fixed amount of margin to each trade, the entire account balance acts as a shared buffer. A profitable position can help support a losing one, which reduces the chance of a single position being liquidated, but it also means a severe loss can draw down your whole balance rather than a walled-off portion.
Cross margin shares one collateral pool across every position, so your full balance defends each trade and gains on one position offset losses on another. Isolated margin walls off a fixed amount of collateral per position, so the most you can lose on that trade is the margin you assigned, but it gets no help from the rest of your account. Cross margin is more capital efficient and resists liquidation longer; isolated margin caps the damage of any single position.
Portfolio margin is a risk-based margining system that sets your collateral requirement based on the total risk of your whole portfolio rather than summing the requirement of each position in isolation. Because offsetting positions reduce net risk, portfolio margin typically requires less collateral than position-by-position margining for a hedged book. It originated in traditional finance for institutional accounts; in crypto, unified cross-margin systems apply the same risk-based logic across options, perpetuals, and spot.
Reg T margin is a fixed, rules-based system that applies a set percentage requirement to each position independently. Portfolio margin is risk-based: it evaluates the net risk of the entire portfolio, recognising that hedged or offsetting positions are less risky together than apart, and typically requires less collateral as a result. Portfolio margin is more capital efficient for hedged books but carries higher minimums in traditional finance.
Neither is universally safer; they manage risk differently. Isolated margin caps the loss on a single position to the collateral assigned to it, protecting the rest of your account, which suits high-risk directional bets. Cross margin resists liquidation on any one position longer because the whole balance supports it, which suits hedged or correlated positions, but a severe adverse move can draw on your entire balance. The safer choice depends on whether you want to contain per-position risk or maximise capital efficiency across a book.
Unified margin is a single collateral account that backs multiple instrument types at once, such as options, perpetual futures, and spot, rather than requiring a separate margin account for each. On Paradex, one USDC-denominated account collateralises positions across all these markets, so unrealised gains on one instrument can support margin on another, and a covered call can be backed by the same spot holding it is written against, all in one place.
Yes. Cross margin delays liquidation compared with isolated margin because your full balance supports each position, but if losses exceed your total available collateral, liquidation still occurs and can draw on the entire account balance, not just a walled-off portion. Leverage amplifies both gains and losses, so any margin trading carries liquidation risk that grows with leverage. Monitoring your margin ratio and using stop losses are essential regardless of margin mode.
A portfolio margin account is an account that uses risk-based margining to set collateral requirements based on the net risk of all positions combined. In traditional finance these accounts carry high minimum balances and are aimed at experienced or institutional traders. The crypto equivalent is a unified cross-margin account, which applies similar risk-based logic across options, perps, and spot without the traditional minimums, as on Paradex.
Cross margin does not automatically increase leverage, but it is more capital efficient, which lets you open larger or more positions with the same balance because the whole account supports them. That efficiency can translate into higher effective leverage if you choose to use it. Higher leverage amplifies both gains and losses and brings liquidation closer, so capital efficiency should be treated as flexibility, not a reason to over-extend.
Yes. Paradex is accessible globally including from India through a self-custodial wallet connection, giving traders a direct route to cross-margin and unified-margin trading without going through a centralised platform. You can trade BTC options, perpetual futures, and spot from a single USDC collateral account on Paradex Chain (StarkNet L2). The same experience applies for traders in Singapore, the UK, Brazil, and other global markets.
Ready to trade with unified margin? Open Paradex, fund one USDC account, and trade options, perps, and spot under a single margin system. Choose cross or isolated per position, and manage your risk with full visibility into your margin ratio and liquidation price.
Low fees, self-custody, and institutional liquidity from the team behind Paradigm. Browse live markets on the stats page or read the documentation.
Trading perpetual futures, options, and other crypto derivatives on margin involves substantial risk. Leverage amplifies both gains and losses, and leveraged positions can be liquidated, resulting in the loss of your entire margin and, in cross-margin mode, your full account balance. This content is for informational purposes only and does not constitute financial advice. Past performance is not indicative of future results. Do your own research before trading.
Paradex is a decentralised protocol. Access may be restricted in certain jurisdictions. Verify your local regulations before using the platform.
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