What Is Trading Margin?
Trading margin is the amount of funds a broker requires as collateral when a trader opens a leveraged position. Margin allows traders to control a position whose total market value is larger than the amount of capital committed as margin.
Margin should not be confused with a trading fee or a maximum possible loss. The margin requirement is related to the size of the position and the leverage available on the account.
Basic Margin Formula
A simplified margin calculation can be represented as:
The approximate margin percentage can also be expressed as:
Example: 1:100 Leverage
Suppose a position has a notional value of $100,000 and the applicable leverage is 1:100.
This is a simplified example. Actual broker margin requirements may differ depending on the instrument, account currency, contract specifications, regulatory requirements and broker policies.
Margin vs. Leverage
Leverage determines how much market exposure can be controlled relative to the required margin. When leverage increases, the theoretical margin percentage required for the same notional position decreases.
However, higher leverage does not automatically make a trade less risky. A larger position can still generate large gains or losses from relatively small market movements.
What Can Affect Required Margin?
- Position size
- Contract size
- Current market price
- Account leverage
- Instrument specifications
- Account currency
- Currency conversion rates
- Broker margin policies
- Tiered or dynamic margin requirements
- Applicable regulatory restrictions
What Is Free Margin?
Free margin generally refers to the portion of available account equity that is not currently being used as required margin for open positions. It can be affected by open trade profits and losses, existing margin requirements and account equity.
What Is a Margin Call?
A margin call can occur when account equity falls to a level where the broker's margin requirements are no longer adequately covered. Brokers may have specific margin-call and stop-out rules.
Traders should always check their broker's current margin, liquidation and stop-out policies rather than relying solely on a calculator estimate.