Free Margin and the Cost of Opening One More Trade

[Fairman]

Free Margin and the Cost of Opening One More Trade

Scenario: a trader has 6,000 dollars of balance. Open positions use 1,800 dollars of margin, and show a floating loss of 500 dollars. They want to open another position that requires 1,200 dollars of margin.

Work it out. Equity is balance plus floating profit or loss: 6,000 minus 500, which is 5,500 dollars. Free margin is equity minus used margin: 5,500 minus 1,800, which is 3,700 dollars.

The new position needs 1,200 dollars, so it fits. After opening, used margin becomes 3,000 dollars, free margin becomes 2,500, and margin level is 5,500 divided by 3,000, or 183 percent.

Now think beyond what the platform allows. Is the trade wise? The new position adds risk, and the existing position is already losing. If both are on the same currency theme, a further adverse move hits both.

The platform's willingness to open a trade is not advice. It only checks whether free margin covers the requirement.

Check three things before opening. The total risk after the trade, in dollars and percent. The margin level after the trade, with a personal floor such as 400 percent. And correlation with existing positions.

Some traders set a rule that margin use never exceeds 20 or 30 percent of equity.

Takeaway: free margin tells you what is possible, and your risk limits tell you what is sensible.

Practical step: define a personal maximum for used margin as a percentage of equity.

[Fairman]

It's worth calculating the margin level before the new trade as well. With equity of 5,500 and used margin of 1,800, it's about 306 percent. After opening, it falls to 183 percent. That's a big drop from one trade, and if the trader's personal floor is 400 percent, as suggested, they were already below it before adding the new position. The platform allows it, but the trader's own rule would say no. This is exactly why personal limits matter: the platform's only concern is whether there's enough free margin, not whether the trade makes sense for your risk.

[Amanhasnoname]

The part that changed my habits was the margin level after the trade, not the free margin figure. A few years ago I had an account of about four thousand dollars with two losing positions open, and the platform happily let me add a third because free margin still showed over two thousand. The new trade took my margin level from around 320 percent to under 200, and an ordinary spike at the rollover was enough to make me close everything in a hurry.

Since then I use a rule that sits on top of the platform's. Before opening anything, I write down what the margin level would be after the trade, and if it falls below 400 percent I don't take it unless I close something else first. It sounds strict, but it has stopped me from stacking correlated positions on a bad day more times than I can count.

I also look at the floating loss separately. If the existing position is already red, I'd rather wait for it to resolve than average into it with fresh margin.