Free Margin Explained: Why Zero Free Margin Locks You Out

The Locked-Out Screen: What Just Happened to Dana

Dana is watching EUR/USD tick higher, exactly the move she planned for. As of today, EUR/USD is trading around 1.1595–1.1598, having climbed roughly 0.19% on the session. She clicks to open a second position to size up, and instead of a fill, she gets a rejection. Her balance says $2,000. Her equity says $2,100, she is actually up on the trade. But one field on her screen reads zero. Free margin: $0.

Not her balance. Not her equity. A completely different number, and that number is the one deciding whether she trades again today. Most new traders never check it until it is too late. By the end of this article, you will know exactly how that zero got there, and how to see it coming three trades before it happens.

Used Margin: The First Half of the Puzzle

Here is where that zero starts. Every time a broker lets you open a position with leverage, they set aside a slice of your account as a good-faith deposit. That slice is called required margin, and it is different for every open trade depending on position size and leverage used.

Used margin is simply the total of every required margin across every position you currently have open. One trade, one required margin number. Three trades open at once, three required margin numbers added together. That total is used margin, and it is the first half of the puzzle that eventually froze Dana's account.

• One open trade = required margin for that trade only
• Three open trades = sum of all three required margins
• Used margin never moves on its own once trades are open — only new trades or closed trades change it

The Free Margin Formula (Same Number, Different Label)

Now take your equity — that's your balance adjusted for whatever your open trades are doing right now, up or down — and subtract used margin, the total tied up in those open positions. What is left over is free margin. It is the portion of your money that is not locked into a trade, sitting there ready to be used.

Equity minus used margin equals free margin. That is the entire formula, and everything else in this piece is just what happens to the numbers on either side of that subtraction.

If your platform does not literally say 'free margin' anywhere, look for one of these instead — it is the same number underneath.

The Two Jobs of Free Margin

So why does this number matter enough to block a trade? Free margin does two jobs at once.

1. Gatekeeper — Before your broker lets you open anything new, it checks whether you have enough free margin to cover that trade's required margin. No free margin, no new position, full stop.
2. Cushion — While a trade is open and moving against you, it is free margin that absorbs that pain first, before your broker ever considers a margin call or a stop-out.

Here's the key though: the exact same free margin number means something completely different depending on how volatile the pair is and how much room your stop actually needs. Context always beats the raw number — where you stand relative to that room is what actually matters.

Floating Profit Lifts It, Floating Loss Drains It

Say Dana's EUR/USD long moves further in her favor. That unrealized gain is called floating profit, and it flows straight into equity — equity rises in real time as the trade prints green. Since free margin equals equity minus used margin, and used margin does not move while the trade is open, that entire gain shows up as extra free margin.

If her floating profit grows by $300, her free margin goes up by roughly the same $300. Winning trades quietly hand you more room to trade with.

Now flip it. If price turns against the position, that is floating loss, and it drags equity down the exact same way profit pushed it up — dollar for dollar. Used margin still hasn't moved, so every dollar of that drawdown comes straight out of free margin. The cushion is shrinking, and it's shrinking faster than most traders are watching.

Watch Free Margin Move, Live on EUR/USD

Before going further, pull up your own EUR/USD chart right now — live — next to your account panel. With the pair sitting near 1.1595 and having ranged between roughly 1.1570 and 1.1599 intraday, you have real movement to watch. Find whatever field is doing this job for your broker — free margin, usable margin, available margin, whatever they call it — and just watch it for thirty seconds while price moves.

You'll see it tick with every candle: rising when the pair moves your way, falling when it doesn't. That live tick is the entire idea happening in real time in front of you, on the exact pair we've been using the whole way through.

The Full Math: No Trades vs. One Trade Open

No Trades Open

Say Dana's account has a $2,000 balance and no trades open at all. With nothing open, there is no required margin anywhere, which means used margin is zero. Equity — with no floating profit or loss to adjust it — is just the balance, $2,000. Free margin is equity minus used margin: $2,000 minus $0, so free margin equals the full $2,000.

One Trade Open: The Full Math

Now Dana actually places the trade. It's a bullish continuation setup — about as basic as it gets, not some complex multi-candle reversal. Her entry trigger is a clean break above the recent high on EUR/USD, which today sits near the 1.1599 intraday high. Her stop goes a few pips below the last swing low, with a little wiggle room so normal noise doesn't tag her out, and her target sits at twice that risk — a 2:1 reward.

Remember: a setup like this never guarantees a winner. Breakouts fail constantly — the stop is the only thing that actually saves the account. Once that trade is live, required margin gets carved out of her balance, used margin becomes a real number for the first time, and every tick from that point on pushes her free margin up or down depending on which way price goes.

Notice: even with the trade in profit, used margin is now locked away, so free margin drops from $2,000 to $1,950 — it's still healthy, just no longer equal to equity. That gap between equity and free margin is exactly what opening a position creates, and it's the gap that eventually closes in on Dana later in her session.

Zero and Below: Why the Door Slams Shut

Equity always equals used margin plus free margin — rearrange the formula and that's the identity underneath everything. As losses stack on open trades, free margin keeps shrinking toward zero while used margin stays fixed. Once free margin hits zero, the broker's gatekeeper function kicks in immediately: no new trade can be opened, no matter how good the setup looks, because there's nothing left to post as required margin for it.

Push past zero and free margin turns negative, and that's a different, more serious problem. At that point the cushion is gone entirely, and depending on your broker's margin call and stop-out levels, existing positions can start getting force-closed automatically — not because you chose to exit, but because the platform did it for you to protect against a negative balance.

• Free margin above a comfortable threshold — you can size up or add new trades
• Free margin low but positive — you're locked out of new trades but existing ones survive
• Free margin at or near zero — margin call territory, act now
• Free margin negative — stop-out risk, broker may close positions automatically

Free Margin Recap

Free margin is equity minus used margin — the money not locked into a trade, sitting ready to be used. It does two jobs: gatekeeper for new trades, cushion for existing ones. Floating profit lifts it dollar for dollar; floating loss drains it dollar for dollar. Whatever your broker calls it — free margin, usable margin, available margin — it's the same number, and it's the one field that decides whether your next click gets a fill or a rejection.

Dana's zero didn't appear out of nowhere. It was the predictable result of used margin staying fixed while floating losses ate through her cushion, trade after trade. The fix isn't complicated: check free margin before every new entry, not after the rejection screen.