Direct answer
A worked example of margin risk shows how a position’s unrealized losses can shrink an account’s available margin relative to the margin requirement, potentially leading to a margin call and/or forced closing. The core idea is numeric: compare what you can still use (available margin) to what the broker/platform requires you to keep (required margin).
Mechanism or definition
Margin is collateral you post to open and hold a leveraged position. In practice, providers reserve part of your account equity as required margin. The remaining portion is often described as available margin.
Margin risk is the risk that, as the market moves against your position, the account’s equity declines and the available margin falls to the point where the provider’s rules no longer allow the position to be maintained. The exact trigger level (for example, the threshold that initiates a margin call) is not the same across providers and jurisdictions.
To discuss a worked example without assuming live prices, we separate the stable mechanics (equity changes due to profit/loss, margin reserved) from variable conditions (execution quality, costs, and provider-specific rules).
Evidence or example
Assumptions (state everything you need to compute)
- You start with account equity: 10,000 (currency units).
- You open one leveraged trade and the provider reserves required margin: 2,000.
- Available margin at open equals equity minus required margin: 10,000 − 2,000 = 8,000.
- We ignore commissions and financing, and we model only the position’s profit/loss.
- The provider will intervene once equity falls enough that available margin becomes zero (this is a simplification used only to illustrate arithmetic; real thresholds differ).
Step-by-step scenario
Open:
- Equity = 10,000
- Required margin = 2,000
- Available margin = 8,000
Market moves against the position: Suppose unrealized losses increase to 8,000.
- Equity becomes 10,000 − 8,000 = 2,000
- Required margin stays 2,000 (simplified)
- Available margin becomes 2,000 − 2,000 = 0
Result under the simplified rule:
- With available margin at zero, the provider’s intervention becomes likely because the account no longer has excess margin buffer.
- If the provider’s actual rule requires a buffer larger than zero, intervention could occur earlier than this point.
Material failure mode to understand
Even if the calculation above uses a simplified intervention at zero available margin, real outcomes can differ because:
- costs and financing change equity,
- the required margin may change as position size or terms differ,
- execution can create additional losses (for example, rapid price movement or delayed fills).
This is why margin risk is about account resilience under adverse price moves, not about a guaranteed outcome.
Limitations and risks
- Provider-specific thresholds: Margin call and forced closure rules vary. The “available margin reaches zero” rule is only an illustrative model.
- Costs and execution: Spreads, commissions, swap/financing, and order execution can change the equity path, making the simplified arithmetic optimistic or pessimistic.
- Dynamic margin requirements: In some arrangements, required margin can change with exposure and terms, so required margin may not be constant.
Verification and next question
To independently verify your own understanding, reproduce the same comparison using your own stated inputs:
- Start equity (equity at trade open)
- Initial required margin
- How unrealized profit/loss changes equity
- Your provider’s published margin call / close-out trigger rules
A next useful question is: How does your provider define “available margin,” and what exact equity threshold triggers a margin call or forced closure?