At a normal broker: nothing happens yet
80% margin usage on equity is the same as a margin level of 125%. Many brokers send a margin call somewhere around a 100% margin level and start closing trades, the stop out, at a lower level such as 50%. The exact levels depend on your broker. So at 80% you're closer to trouble, but no alarm has gone off.
At a prop firm with a margin rule: it can count
Some prop firms don't let the margin of your open trades go above a set share of the account, for example 80%. Going over can be treated as a breach, get a payout refused, or have the profits from those trades removed. The exact outcome is in your firm's terms, and it's worth reading that paragraph twice.
The frustrating part is that the account can be in profit when it happens. The rule isn't about losing money. It's about how much of the account you had committed at once.
Five ways traders drift into 80%
- Adding trades. Each trade looks small on its own. Three of them together don't.
- Price moving. Margin is recalculated with the price. Measured on balance, a gold position that used 70% of the account at 4,200 uses 70.7% at 4,242. On equity, the floating profit or loss from that move counts for much more.
- Floating losses, if your firm uses equity. On a $10,000 account, 0.16 lot of gold at 1:10 uses $6,720 of margin, 67.2%. With a $600 open loss, equity is $9,400 and usage is about 71.5%, before counting the small change in margin from the price move.
- Lower leverage on the funded account. If your funded account has lower leverage than your challenge did, margin rises with it. A trade that used 25% of the account at 1:100 uses 83% at 1:30.
- Exchange rates. If your account isn't in dollars, the conversion changes the margin figure every day.
From 42% to a breach in one afternoon
A $10,000 account at 1:30 (1:20 on indices) with an 80% rule measured on equity:
- 0.30 lot of gold at 4,200: $4,200 of margin, 42%.
- Add 0.75 lot of EURUSD: $2,850 more, 70.5% in total.
- The two trades drift $400 into the red combined, so equity is $9,600. Usage is now 73.4% without a single new click.
- Add 0.5 lot of NAS100 at 30,600: another $765, and usage is 81.4%. Breach.
None of the three trades was large. What broke the rule was adding the last one without re-checking the number.
How much fits under 80% on a $10,000 account
| Instrument | At 1:30 (NAS100 1:20) | At 1:100 |
|---|---|---|
| Gold at 4,200 | 0.57 lots | 1.90 lots |
| EURUSD at 1.1400 | 2.10 lots | 7.01 lots |
| NAS100 at 30,600, contract 1 | 5.22 lots | 26.14 lots |
Those are ceilings, not targets. A position that size leaves no room for price moves or a second trade.
If you're already close
- Don't open anything else until usage is back down.
- If you need room, close part of a position. Closing all or part of a position is the only way you control to cut margin right away.
- Check whether your firm measures balance or equity, so you know which number to trust.
Habits that keep you under it
- Set your own ceiling below the firm's, for example 60% to 70% when the rule is 80%.
- Work out usage before each new trade, with your open trades included.
- For the same money at risk, a wider stop means fewer lots and less margin. How many lots to trade on a funded account shows the one-line formula behind this.
- Avoid stacking trades that are really the same bet, like long EURUSD and long GBPUSD.
The 80% margin rule calculator shows SAFE or BREACH for your next trade, and the most you can open without crossing the line.