What Is Margin: Explained in Simple Terms

Margin is the portion of funds that a broker freezes as collateral for an open position. The key thing a beginner needs to understand: margin is not a commission or a fee for a service, but collateral. While the trade is open, this money is unavailable for other positions, and after closing it returns to the account. Confusing margin with commission is one of the typical beginner mistakes.

How margin is calculated

The size of margin depends on position size and leverage. At 1:100 leverage, a position with a nominal of 100,000 requires about 1,000 as margin (1 percent of the nominal). The higher the leverage, the smaller the collateral for the same size: at 1:500 the same position needs only about 200. This is convenient (you can trade with little capital) but also more dangerous, the "cushion" in case of a move against you becomes thinner.

Margin and leverage

Margin and leverage are closely linked: leverage determines what share of the nominal you must post as collateral. High leverage equals small margin for a large position. But it is important to understand: small margin does not mean small risk. Risk is set by position size and the stop, not by the size of the collateral. It is a mistake to think that with high leverage and small margin you are risking little: in reality a large nominal means high sensitivity to a price move.

Free margin and margin level

Two important metrics are tied to margin. Free margin is the funds available for new trades (equity minus used margin). Margin level is the ratio of equity to used margin as a percentage, the key indicator of account health. When the loss on a position grows, free margin melts and the margin level falls. If it drops to a critical threshold, a margin call comes, then a stop-out, the forced closing of positions.

Why it matters to watch margin

You need to control not only the direction of a trade but also what share of the deposit the margin occupies. If most of the account is frozen under open positions, you have almost no buffer: a small move against you will drop the margin level to the threshold and trigger a forced closure. Conversely, with modest margin use the account rides out pullbacks calmly. So margin is an indicator of how "loaded" your account is and whether it is close to the danger zone.

The practical takeaway

Treat margin as an indicator of account load, not as a cost. Keep size such that used margin occupies a small part of the deposit, leaving a buffer of free margin. Watch the margin level, especially with several open positions. Margin is the price of entering a leveraged position: by itself it returns to you, but while the trade is open it limits your options and determines how close you are to a margin call. Understanding margin is as important as understanding trade direction: one determines potential, the other the stability of the account.

This material is for educational purposes and is not individual investment advice.