Smart Lot Management and Balance Ratio Control in MT5 Copiers – Other – 23 October 2025

One of the most sensitive areas in any MT5 trade copier is lot management — how the slave determines trade volume in proportion to the master.
In my latest copier build, I implemented several adjustable parameters to give traders full control over risk and position sizing.

Here’s a quick summary of how the system handles lot scaling:

1. Balance Ratio Control
   When UseBalanceRatio = true, the copier automatically compares the balances of master and slave accounts.
   This ensures that if a slave has half the balance of the master, it will open trades at half the volume — keeping risk proportional.

2. Lot Multiplier (LotMultiplier)
   A flexible way to scale trades.
   For instance, with a multiplier of  0.6 , a 1.00-lot trade on the master becomes a 0.60-lot trade on the slave.
   This simple control is often enough for most mirror setups.

3. Fixed Lot Option (FixedLotSize)
   For those who prefer full consistency, you can disable automatic scaling and use a static lot size.
   When set to a non-zero value, all copied trades use that lot, regardless of master balance or multiplier.

4. Maximum Lot Limit (MaxLotSize)
   To prevent accidental over-sizing, a safety limit is applied so that no trade exceeds the specified maximum volume.

5. Free Margin Protection
   If FreeMarginPercent is defined, the copier checks available margin before placing any trade — ensuring that only trades within safe margin limits are copied.

This combination of controls gives users both flexibility and safety, whether they run identical accounts or mirror trades to smaller risk accounts.
I’ve found that balance-based scaling combined with a reasonable multiplier provides the most stable performance over time.

If you’ve tested alternative methods for balancing risk between accounts, I’d be glad to hear about your experiences.

You can download the latest copier version from the link below.