What Is Margin in Trading?

Margin is one of those terms that confuses a lot of new traders. It sounds like it might mean "profit margin" from the business world, but in trading it means something very different. Here's a clear, complete explanation.

The Simple Definition

Margin is the deposit required to open and maintain a leveraged trading position. It's not a fee or a cost — it's collateral that your broker holds while your trade is open. Think of it like a security deposit.

When you close your trade, the margin is released back to your account (along with your profit or minus your loss).

Margin and Leverage — How They Connect

Margin and leverage are two sides of the same coin. Leverage is expressed as a ratio (50:1, 100:1) while margin is expressed as a percentage.

The relationship is simple: Margin % = 1 ÷ Leverage Ratio × 100

• 50:1 leverage = 2% margin requirement
• 100:1 leverage = 1% margin requirement
• 200:1 leverage = 0.5% margin requirement
• 10:1 leverage = 10% margin requirement

So at 50:1 leverage, to open a $100,000 position (1 standard lot), you only need $2,000 as margin.

Types of Margin

Required Margin

The amount your broker needs to open a specific position. Calculated as: Position Size ÷ Leverage.

Used Margin

The total amount of margin currently being used across all your open positions.

Free Margin

The amount of money in your account that is NOT being used as margin. This is available to open new trades or absorb losses. Free Margin = Account Equity − Used Margin.

Margin Level

A percentage that shows the health of your account. Margin Level = (Equity ÷ Used Margin) × 100. Most brokers issue a margin call when this drops to 100% and close positions at 50%.

What Is a Margin Call?

A margin call happens when your account equity drops too low relative to your used margin — typically when losses eat into your free margin. At this point your broker will alert you to deposit more funds or close positions.

If you don't act fast enough, your broker will automatically close your positions (starting with the most unprofitable ones) at the stop-out level — often 50% margin level.

How to Avoid a Margin Call

• Never use all your margin — always keep plenty of free margin as a buffer
• Use stop losses on every trade — this limits how much any single trade can damage your account
• Size positions correctly — never risk more than 1-2% of your account on one trade
• Don't over-leverage — just because 500:1 leverage is available doesn't mean you should use it
• Monitor your margin level — keep it above 200% for safety

Margin in Different Markets

Forex

Forex typically offers the highest leverage (up to 500:1 in some jurisdictions, regulated to 30:1 in the EU and UK). Margin requirements are low, making it accessible but also risky.

Stocks

In the US, the SEC requires at least 50% margin for stock purchases (2:1 leverage). Maintenance margin is typically 25%.

Futures

Futures use initial margin (to open) and maintenance margin (to keep a position). These are set by the exchange and vary by contract.

Key Takeaways

• Margin is collateral, not a fee — you get it back when you close your trade
• Higher leverage = lower margin requirement = more risk
• Always maintain enough free margin to absorb losses
• A margin call means your account is in danger — act immediately
• Use position sizing and stop losses to protect your margin