Direct answer
Required margin in forex is the amount of money a broker requires you to keep available (reserved) in your trading account to hold an open position. It acts as collateral for the position, based on how large the position is and the leverage rules applied.
Explanation: how it works
A forex trade typically involves control of a notional position size that is larger than the cash you pay. Leverage describes that relationship. Because brokers allow positions with only a portion of the position value in cash, they require margin.
Required margin is usually calculated from:
- Position size (notional): larger positions generally require more reserved funds.
- Leverage: higher leverage can reduce required margin per unit of position, because you control more notional per amount of account funds.
- Contract/market specifications: instruments can differ in how margin is applied due to contract size or other rules.
What matters operationally is available margin versus required margin. When you open a trade, the broker reserves the required margin. As the trade moves, your account’s equity and available funds can change due to unrealized gains or losses.
Example and checks (conceptual)
Imagine you open a forex position. The broker determines a required margin for that trade and reserves it, reducing your available margin. If later the position moves against you, your equity may decline. If available margin drops below what the broker requires, the broker may take action to manage risk, such as a margin call (requesting additional funds) or forced closure (closing positions) depending on the broker’s rules.
Independent checks you can do with your own broker’s materials:
- Look for a margin requirements or margining section in your account documentation.
- Compare how margin changes when you adjust position size and leverage.
- Verify the exact meaning of terms like equity, available margin, and margin level in the broker’s definitions.
Limitations and what required margin does not mean
Required margin is not a prediction of outcomes. It does not guarantee that a trade will be profitable or that losses cannot occur. It only describes the broker’s requirement to keep funds reserved while a position is open.
Also, required margin can vary by instrument and broker policy, so the most reliable definition is the one published by the broker for your specific account and product. Because the amount reserved depends on leverage, position size, and evolving account equity, the exact number can change over time as your positions and account balance change.