Initial Margin vs Variation Margin: How Both Types of Collateral Work in Futures and OTC Markets

Initial margin vs variation margin defined Initial margin is collateral posted before a trade is opened — a deposit held against the possibility that the position loses money before it can be closed out. Variation margin is the daily cash settlement of gains and losses on an open position — moving money between winner and loser each day to reflect that day’s price change. Both exist to protect the counterparty (and the clearinghouse) from the risk that a trader defaults before their position is closed. In exchange-traded futures, both concepts are handled by the clearing house automatically. In over-the-counter (OTC) derivatives, the same concepts apply under different regulatory frameworks and naming conventions.

Table of Contents

1. Why Margin Exists: The Clearinghouse’s Problem
2. Initial Margin: The Upfront Deposit
3. Variation Margin: Daily Mark-to-Market Settlement
4. Initial Margin in Exchange-Traded Futures vs OTC Derivatives
5. SPAN Margin Methodology: How Exchanges Calculate Initial Margin
6. ISDA SIMM: The OTC Derivatives Standard
7. Margin Calls: What They Are and What Happens If You Miss One
8. The Close-Out Risk Window: Why the 5–7 Day Period Matters
9. Maintenance Margin: The Third Concept You Need to Know
10. Frequently Asked Questions
11. Key Takeaways

Why Margin Exists: The Clearinghouse’s Problem

Start with the problem that margin solves.

When two parties agree on a futures trade, one will make money and one will lose money as prices move. The losing party might not pay — either because they cannot (they have run out of money) or because they choose not to (they walk away from the obligation). In either case, the winning party suffers.

Exchanges solved this problem by inserting a clearinghouse — a central counterparty that becomes the buyer to every seller and the seller to every buyer. Instead of two parties facing each other directly, both face the clearinghouse. This eliminates direct counterparty risk between traders.

But it creates a new problem: the clearinghouse now faces the risk that either party defaults. If a trader opens a large position that goes badly wrong, the clearinghouse needs to close it out without suffering a loss. Margin is the mechanism that ensures the clearinghouse is protected during the time it takes to close a losing position.

Two types of risk during close-out:

1. Gap risk at default: the moment a trader defaults, the clearinghouse needs cash to start closing the position. Initial margin covers this.
2. Daily drift of losses: as long as a position is open and moving against the holder, losses accumulate daily. Variation margin collects these losses each day so they do not compound into an uncollectable balance.

These two risks require two different collateral mechanisms — which is exactly why initial margin and variation margin are separate concepts.

Initial Margin: The Upfront Deposit

Initial margin (IM) is the collateral deposited before a trade is opened. Think of it as the clearinghouse (or your counterparty) requiring a security deposit.

Initial margin is not a payment for the commodity or the contract. It is collateral held in a segregated account that can be used if the trader defaults and their position needs to be closed out at a loss.

Key characteristics of initial margin:

• Refundable: When the position is closed (not just when it expires, but if you exit early), initial margin is returned — assuming no default occurred.
• Covers the close-out risk window: IM is sized to cover the expected loss if the position moves adversely over the time it takes to close out a defaulted position (typically 5–7 trading days for exchange-traded futures; longer for OTC derivatives).
• Changes with volatility: During periods of high market volatility, exchanges increase IM requirements. When markets calm, IM requirements may be reduced. IM is recalculated regularly (though not daily, unlike VM).
• Can be posted as cash or eligible securities: US Treasury bonds, government bonds, and sometimes equities can substitute for cash as IM, though with haircuts (deductions for market value uncertainty).

Example:

A grain trader buys one CBOT corn futures contract — 5,000 bushels. CBOT’s initial margin requirement for corn might be around $1,200 per contract. The trader must post $1,200 as IM before the exchange accepts the trade. The corn position itself represents roughly $24,000 of notional value at $4.80/bushel. IM of $1,200 means the exchange can withstand roughly a 5% adverse move in corn prices before the IM is exhausted — enough time to close the position if the trader defaults.

Variation Margin: Daily Mark-to-Market Settlement

Variation margin (VM) is the daily cash settlement of gains and losses on an open futures position.

At the close of each trading day, the exchange calculates the difference between:

• The price at which a position was established (or the previous day’s settlement price), and
• Today’s settlement price.

If the position has gained value, the clearinghouse credits cash to the trader’s account. If the position has lost value, the clearinghouse debits cash from the account. This daily settlement process is called mark-to-market.

Why daily settlement matters:

By collecting losses daily, the clearinghouse prevents a situation where a trader holds a large losing position for weeks, accumulating a massive unpaid debt. Without daily mark-to-market, a trader could run up unlimited losses that become impossible to collect.

The practical consequence: a futures position is not just a paper gain or loss — it is real cash flowing in and out of your account every day.

Example:

On Monday, a trader buys one WTI crude oil futures contract at $80.00/barrel. Each contract covers 1,000 barrels, so the position is worth $80,000. On Tuesday, the settlement price moves to $81.50/barrel. The clearinghouse credits $1,500 (1,000 barrels × $1.50) to the trader’s account as variation margin. On Wednesday, the price falls to $79.00/barrel. The clearinghouse debits $2,500 (1,000 × $2.50) from the account.

The trader’s initial margin deposit of (say) $4,500 remains untouched through these daily fluctuations — VM flows through the account separately.

Initial Margin in Exchange-Traded Futures vs OTC Derivatives

This is the most important nuance in the entire IM/VM topic, and it is almost never explained clearly.

The definitions of initial margin and variation margin differ between exchange-traded futures and over-the-counter (OTC) derivatives. The names are the same. The mechanics are different.

Exchange-traded futures:

Feature	Initial Margin	Variation Margin
Purpose	Close-out risk buffer	Daily P&L settlement
Timing	Posted before trade	Collected/paid daily
Nature	Refundable collateral	Cash settlement (not returned)
Set by	Exchange (via SPAN or similar)	Exchange (mark-to-market)
Eligible assets	Cash, eligible securities	Cash only (typically)

OTC derivatives (bilateral, non-cleared):

Under the BCBS-IOSCO Uncleared Margin Rules (UMR) — a global regulatory framework phased in from 2016 — OTC derivatives traded outside a central clearinghouse are subject to:

• IM: calculated using the ISDA Standard Initial Margin Model (SIMM) or a schedule-based approach, and posted to a third-party custodian (not to the counterparty directly). This segregation protects IM from the counterparty’s bankruptcy.
• VM: exchanged daily (or more frequently) based on mark-to-market valuation of the OTC derivative.

The critical difference from futures: OTC IM is held by a third-party custodian, not by the counterparty, ensuring it cannot be used by the counterparty if it goes bankrupt. In futures, IM is held by the clearinghouse — a neutral central counterparty.

Also: OTC derivatives IM is typically not netted across all positions the way exchange IM is. This creates significantly larger IM requirements in OTC markets compared to equivalent positions on exchange.

SPAN Margin Methodology: How Exchanges Calculate Initial Margin

SPAN stands for Standard Portfolio Analysis of Risk — the initial margin calculation system developed by the Chicago Mercantile Exchange (CME) in 1988. It is now used by most major commodity exchanges worldwide.

The core idea behind SPAN: rather than calculating IM for each futures position individually, SPAN analyses an entire portfolio of positions and calculates the worst-case scenario across a range of possible market moves.

How SPAN works (in plain English):

SPAN takes a trader’s full portfolio — say, long crude oil futures, short natural gas futures, long crude oil options — and runs it through 16 hypothetical market scenarios. These scenarios vary the underlying price and the implied volatility by different amounts (up/down in different combinations).

The “scan risk” is the worst loss across all 16 scenarios. SPAN adds adjustments for:

• Short option minimum: options have gamma risk that SPAN’s scenario grid may understate.
• Inter-commodity spread credits: if two positions offset each other’s risk (e.g., long crude oil and short heating oil — both petroleum products), SPAN may reduce IM to reflect the partial hedge.
• Delivery risk: if positions are near expiry and delivery is approaching, IM may increase.

The result is a single dollar figure: the portfolio’s initial margin requirement. SPAN is recalculated at least daily and sometimes intraday if market conditions change significantly.

SPAN is important for commodity users because it means IM for a hedged position (say, long physical crude oil, short crude oil futures) is much lower than IM for an outright speculative position. Hedgers pay less margin — which makes economic sense.

ISDA SIMM: The OTC Derivatives Standard

For OTC derivatives not cleared through a central clearinghouse, the equivalent of SPAN is the ISDA Standard Initial Margin Model (SIMM).

ISDA stands for the International Swaps and Derivatives Association — the industry body that governs the legal framework for OTC derivatives globally. SIMM was developed by ISDA and industry participants after the 2008 financial crisis, as regulators required that OTC derivatives be subject to initial margin requirements similar to exchange-traded contracts.

How ISDA SIMM works:

SIMM is a sensitivity-based model. It takes the risk sensitivities of each OTC derivative in a portfolio — how much the derivative’s value changes for a 1-basis-point move in interest rates, a 1% move in commodity prices, etc. — and aggregates them into a portfolio-level IM figure.

Commodity OTC derivatives under SIMM are categorised into commodity classes (energy, metals, agriculture, etc.). Each class has its own risk weights reflecting historical volatility. The SIMM calculation then aggregates within and across classes, accounting for diversification benefits.

Why SIMM matters:

SIMM became mandatory for in-scope counterparties under the Uncleared Margin Rules (UMR). The phases of UMR implementation, which ran from 2016 to 2022, brought thousands of financial firms and large non-financial companies (including major commodity users) into scope for IM requirements on OTC swaps and forwards.

For a large manufacturing company that uses commodity swaps (say, a copper producer that fixes forward prices via OTC copper swaps), SIMM determines how much collateral must be posted. This has materially increased collateral requirements for OTC hedging and has been a factor pushing some OTC commodity hedging towards cleared alternatives where IM requirements may be lower.

Margin Calls: What They Are and What Happens If You Miss One

A margin call occurs when your margin account balance falls below a required threshold and you must post additional collateral.

How it happens:

For exchange-traded futures, a margin call is triggered when variation margin payments (daily losses) erode your account balance below the maintenance margin level (explained in the next section). The broker notifies you — typically by close of the following business day’s trading session — that you must deposit additional funds.

For OTC derivatives under UMR, IM is recalculated based on the current portfolio using SIMM. If IM rises (because new trades were added, or because market volatility increased the SIMM requirement), additional IM must be posted — typically within 1 business day.

What happens if you don’t meet a margin call?

In exchange-traded markets:

1. The broker may immediately close (liquidate) some or all of your open positions to bring the account back into compliance.
2. Any losses from forced liquidation are charged against your account.
3. If the liquidation proceeds do not fully cover losses, the trader owes the shortfall to the broker.
4. If the broker cannot collect, the clearinghouse covers the loss from a default fund — funded by contributions from all clearing members.

Missing a margin call is effectively a default event. In commodity markets, forced liquidations during margin calls can sometimes move prices — this is most visible in agricultural futures during periods of sharp price moves.

Speed matters:

In futures markets, margin calls must typically be met by the start of trading the next morning. In OTC markets under UMR, the settlement cycle is T+1 (one business day). The regulatory framework was designed to ensure that margin is collected quickly enough that a default during the collection period cannot overwhelm the clearinghouse.

The Close-Out Risk Window: Why the 5–7 Day Period Matters

Initial margin is sized based on a specific assumption: the time it takes to close out a defaulted position. This is called the margin period of risk (MPOR) or the close-out risk window.

For exchange-traded futures, the standard MPOR is 5 business days. The logic:

• Day 0: Trader defaults.
• Days 1–2: Clearinghouse identifies the default and assesses the position.
• Days 3–5: Clearinghouse closes the position in the market.

During those 5 days, the market can keep moving against the defaulted position. IM must be large enough to cover the expected worst-case loss over that 5-day window at a high confidence level (typically 99%).

For uncleared OTC derivatives, the standard MPOR is 10 business days — longer because OTC positions are less liquid, contracts may be bilateral and harder to close quickly, and legal documentation may need to be resolved before positions can be transferred or terminated.

Higher MPOR = higher IM requirement. This is one of the structural reasons OTC derivatives carry higher IM than equivalent exchange-traded futures: the close-out window is longer, the risk window is wider, and more collateral is required to cover it.

Maintenance Margin: The Third Concept You Need to Know

Initial margin and variation margin are the two primary concepts. But in exchange-traded futures, there is a third related term: maintenance margin.

Maintenance margin is the minimum account balance required to keep a futures position open. It is set below the initial margin level.

Concept	Definition	Typical Level
Initial margin	Required to open a position	$4,500 (NYMEX crude example)
Maintenance margin	Minimum to keep position open	$4,000 (NYMEX crude example)
Margin call trigger	When account falls below maintenance	At $4,000
Margin call requirement	Restore to initial margin level	Must return to $4,500

The buffer between initial and maintenance margin absorbs small daily losses without triggering immediate margin calls. Only when the account falls below maintenance margin does a call go out.

This design prevents constant margin calls from normal day-to-day market fluctuation while still ensuring the clearinghouse collects before losses become too large.

Frequently Asked Questions

What is the difference between initial margin and variation margin?

Initial margin is a deposit posted before opening a position — it is refundable collateral held as a buffer against potential default losses. Variation margin is the daily cash settlement of gains and losses on an open position — it is not collateral but actual money moving between winners and losers each day based on that day’s price change.

Can initial margin be posted in forms other than cash?

Yes. Most exchanges accept US Treasury bonds, other government bonds, and sometimes equities as initial margin, subject to haircuts (discounts to market value reflecting liquidation uncertainty). Variation margin is almost always required in cash, as it represents immediate daily P&L settlement.

What is SPAN margin?

SPAN (Standard Portfolio Analysis of Risk) is the initial margin calculation methodology developed by the CME Group in 1988. It analyses an entire portfolio of futures and options positions across 16 market scenarios to determine the worst-case loss, then sets IM at a level that covers that scenario. SPAN’s portfolio approach means that hedged positions receive IM credits, reducing costs for genuine hedgers.

What is ISDA SIMM?

ISDA SIMM (Standard Initial Margin Model) is the industry-standard method for calculating initial margin on uncleared (bilateral) OTC derivatives. Required under post-2008 Uncleared Margin Rules, SIMM uses sensitivity-based risk aggregation across commodity, interest rate, credit, equity, and FX asset classes to determine the IM a counterparty must post to a third-party custodian.

Why is OTC derivatives margin typically larger than futures margin?

OTC uncleared derivatives have a longer margin period of risk (typically 10 days vs 5 days for exchange-traded futures), lower liquidity making positions harder to close out quickly, and no netting across positions with multiple counterparties. Each of these factors requires higher IM. This cost differential is one reason regulators have been pushing OTC derivatives towards central clearing.

What happens if I cannot meet a margin call?

If you cannot meet a futures margin call by the required time, your broker will typically liquidate (forcibly close) enough of your positions to bring your account back to the required level. Any losses from that forced liquidation are charged to your account. If the account cannot cover the losses, you owe the shortfall. This is treated as a default event.

Is initial margin the same as a deposit or down payment?

No. Initial margin is not a payment — it is collateral. You do not lose it just because the position moves against you; you lose it only if you default and your position is closed out at a loss that exceeds the IM amount. As long as you keep meeting variation margin calls, your initial margin remains intact and is returned when you close the position.

Key Takeaways

• Initial margin is collateral posted before opening a position; variation margin is the daily cash settlement of gains and losses — they serve different purposes and flow through different mechanisms.
• Variation margin is not returned — it is real money changing hands daily based on the day’s price move. Initial margin is returned when the position is closed, assuming no default.
• The distinction between exchange-traded futures and OTC derivatives is critical: OTC initial margin is held at a third-party custodian (not the counterparty), and OTC margin periods of risk are longer (10 days vs 5 days for futures).
• SPAN (Standard Portfolio Analysis of Risk) is the CME’s methodology for calculating initial margin on exchange-traded futures, using 16 market scenarios to find the worst-case portfolio loss.
• ISDA SIMM is the standard IM calculation model for bilateral OTC derivatives under the Uncleared Margin Rules — required for most large financial institutions and major non-financial commodity users.
• Maintenance margin is the minimum account balance before a margin call is triggered — set below initial margin to provide a buffer against normal daily price fluctuation.
• The 5-day close-out risk window (for futures) and 10-day window (for OTC) are the foundation of IM sizing — IM must be large enough to cover the expected worst-case loss during the time it takes to close a defaulted position.
• Missing a margin call triggers forced liquidation of positions by the broker or clearinghouse — a default event with potentially severe financial consequences.

Related Reading

To deepen your understanding of the topics covered in this article, explore these related guides: the date that can trigger margin changes for physically settled contracts, how margin requirements escalate during the delivery process, how hedgers factor collateral costs into their risk management budgets and the exchange infrastructure where these margin rules apply.