FRM Exam Part I · Central Clearing

CCP Margining: Initial, Variation and Default Fund

Updated 11 October 2026 · Fact-checked

A CCP protects itself from member default with three layers of resources. Initial margin covers potential future losses while a position is closed out. Variation margin settles daily gains and losses. The default fund is mutualised cover for losses beyond a defaulter's margin. You solve questions by following the default waterfall in order.

Understand Margining: Initial, Variation and Default Fund

A central counterparty (CCP) steps between the two sides of a trade through novation. It becomes buyer to every seller and seller to every buyer. If one clearing member fails, the CCP must still honour its obligations to everyone else. Margin and the default fund exist to make that possible.

Variation margin (VM) deals with losses that have already happened. Each day the CCP marks positions to market. Members whose positions lost value pay cash; members whose positions gained receive cash. This stops losses from building up. VM is a transfer of value, not a buffer. It is usually paid in cash.

Initial margin (IM) deals with losses that might happen. If a member defaults, the CCP needs time to close out or auction its portfolio, often a few days (the margin period of risk). Prices can move against the CCP during that time. IM is a buffer sized to cover that move at a high confidence level, usually through a VaR or expected-shortfall style model. The member posts it at the start and it is adjusted as risk changes. It stays with the CCP, typically in segregated accounts, and is returned when the position closes.

Default fund contributions are pooled by all clearing members. They cover losses that exceed the defaulter's IM and its own default fund contribution, in extreme but plausible market moves. Contributions are usually sized to cover the default of the largest one or two members (often called Cover 1 or Cover 2 standards). Because other members' money can be used, the default fund mutualises risk.

The default waterfall is the order in which resources are used when a member defaults: first the defaulter's own resources (IM, then its default fund contribution), then the CCP's own capital (often called skin in the game), then the surviving members' default fund contributions. If those are exhausted, the CCP may use further tools such as assessments (calls for extra funds) or loss allocation under its rulebook. The exact order and extra tools differ by CCP. The key principle is that the defaulter pays first.

Key formulas to remember

Daily variation margin: VM = Current mark-to-market value − Previous mark-to-market value (paid by the party that lost); For a long futures position: VM received = (F_t − F_t-1) × contract size × number of contracts. A negative result means you pay.
Margin period of risk scaling: IM ≈ z × σ_daily × √(MPOR in days) × Position value; A common simple approximation under normal returns with zero mean. z is 2.33 for 99% one-tailed and 1.645 for 95%. Real CCP models are more complex, but this appears in questions.
Default waterfall order: Defaulter's IM → Defaulter's default fund contribution → CCP's own capital → Surviving members' default fund contributions → further CCP tools (e.g., assessments); Check the order given in the question. The defaulter's own resources always come first.
Loss to be mutualised: Loss after defaulter resources = Close-out loss − Defaulter's IM − Defaulter's default fund contribution; If the result is zero or negative, no one else is touched.
Cover standard: Cover 1: fund covers default of largest member. Cover 2: fund covers default of the two largest members.; Sizing is done under extreme but plausible scenarios.

How to solve Margining: Initial, Variation and Default Fund questions

Use this approach for any numerical or conceptual question on CCP margin, default fund or the waterfall.

1Identify which resource the question asks about: IM (future risk), VM (current loss) or default fund (mutualised extreme loss).
2Write down the stated facts: positions, price moves, margin held, default fund contributions, CCP capital, and the waterfall order given.
3For VM, compute the change in mark-to-market value and decide who pays and who receives.
4For IM, check the confidence level and margin period of risk. Scale volatility by √(days) if the question gives a daily figure.
5For a default, compute the close-out loss and subtract the defaulter's resources in order: IM first, then its default fund contribution.
6If a loss remains, subtract the CCP's own capital, then draw on the surviving members' default fund.
7Stop as soon as the loss is fully absorbed. State which layers were used and how much remains.
8Check units and signs. Confirm the answer is not larger than the resources available.

Quickest way: Waterfall subtraction

When to use it: Use for any default loss question with several layers of resources.

List layers in order with their amounts.
Start with the loss and subtract each layer in turn.
The layer where the running total reaches zero is the last one used.
Any amount left unused in later layers is untouched.
For theory questions, remember: VM = current, IM = future, default fund = mutualised tail.

Common mistakes in Margining: Initial, Variation and Default Fund

Treating variation margin as a buffer that is returned.
Both IM and VM are called margin, so students assume they work alike.
Fix: VM is a settlement of realised gains and losses. IM is the buffer held against future loss and returned when positions close.
Using surviving members' default fund contributions before the defaulter's own resources.
Students focus on the word mutualised and forget the defaulter-pays principle.
Fix: Always start with the defaulter's IM and its own default fund contribution. Others' funds come after the CCP's own capital in a standard waterfall.
Forgetting to scale volatility by the square root of the margin period of risk.
Questions give daily volatility but IM covers several days.
Fix: Multiply daily σ by √(MPOR days) before applying the z-score.
Confusing the default fund with initial margin.
Both are collateral posted to the CCP.
Fix: IM is specific to each member's portfolio risk. The default fund is a shared pool sized to cover extreme losses from the largest member defaults.
Getting the direction of variation margin wrong.
Students mix up long and short positions or the sign of the price change.
Fix: If the position gained in value, the member receives VM. If it lost, the member pays. Check with a quick sign test.
Assuming margin removes all risk to the CCP.
Margin sounds like full protection.
Fix: IM covers a chosen confidence level only. Losses beyond it are the reason for the default fund and the rest of the waterfall.

Worked examples

Example 1

A clearing member holds a portfolio worth $200 million with daily volatility of 0.5%. The CCP sets initial margin to cover a 99% one-tailed move over a 5-day margin period of risk, assuming normal returns with zero mean. Use z = 2.33 and √5 = 2.236. Calculate the initial margin, to the nearest $0.1 million.

Show the solution

Formula: IM = z × σ_daily × √MPOR × Position value.
Scale volatility: 0.5% × 2.236 = 1.118%.
Apply z: 2.33 × 1.118% = 2.605%.
Multiply by the position: 2.605% × $200 million = $5.21 million.
Round to the nearest $0.1 million: $5.2 million.

Answer: Initial margin is about $5.2 million.

Example 2

A clearing member defaults. The CCP closes out its portfolio at a loss of $90 million. The defaulter had posted initial margin of $50 million and had a default fund contribution of $10 million. The CCP's own capital in the waterfall is $5 million. Surviving members' default fund contributions total $200 million. How much of the surviving members' default fund is used, and is anything left over?

Show the solution

Start with the close-out loss: $90 million.
Subtract the defaulter's IM: 90 − 50 = $40 million remaining.
Subtract the defaulter's default fund contribution: 40 − 10 = $30 million remaining.
Subtract the CCP's own capital: 30 − 5 = $25 million remaining.
The surviving members' default fund absorbs the remaining $25 million.
Unused portion of the surviving members' fund: 200 − 25 = $175 million.

Answer: $25 million of the surviving members' default fund is used and $175 million remains, so no further tools are needed.

Exam tips

Know the role of each resource in one line: VM covers current losses, IM covers future losses during close-out, default fund covers the extreme tail.
In waterfall questions, read the order stated in the question. Use it even if a real CCP differs slightly.
Watch for the margin period of risk. A multi-day period means scaling by the square root of days.
Expect conceptual questions on procyclicality: IM rising in stressed markets can drain liquidity, and CCPs use buffers or floors to reduce this.
Be ready to explain why mutualised default funds create incentives for members to monitor the CCP's risk management.

Practice questions from Central Clearing

Margining: Initial, Variation and Default Fund in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Margining: Initial, Variation and Default Fund: frequently asked questions

What is the difference between initial margin and variation margin at a CCP?

Initial margin is a buffer posted up front to cover possible losses while a defaulter's positions are closed out. Variation margin is the daily cash settlement of gains and losses on positions. IM is held and returned later. VM is paid and received.

What is the CCP default waterfall?

It is the order in which resources absorb losses after a member defaults. The defaulter's initial margin and default fund contribution go first, then the CCP's own capital, then surviving members' default fund contributions. Many CCPs also have further tools such as assessments, set out in their rulebooks.

Who contributes to the default fund?

All clearing members contribute, usually in proportion to the risk they bring. The pool is used only after the defaulter's own resources are exhausted. Its size is commonly set to cover the default of the largest member or the two largest members.

Do I need to memorise the exact order of the waterfall for FRM Part I?

Know the standard order: defaulter's resources first, then CCP capital, then the surviving members' fund. Questions usually state the layers, so applying the order carefully matters more than memorising any single CCP's rulebook.