Lot sizing: how big each copy is
Each slave picks one of four sizing rules: multiplier, fixed lot, risk percent, or scale by equity.
Every slave decides its own size. Open the slave's settings and go to Lot Sizing & Risk.
The four rules
Fixed Multiplier. The master's lot times your multiplier.
Master trades 1.00 lot, multiplier 0.5: the copy is 0.50 lots.
Fixed Lot. The same size on every trade, whatever the master does.
Fixed lot 0.20: every copy is 0.20 lots.
Risk Percent. The copy is sized so that hitting the stop loss loses your chosen percentage of this account's equity.
Equity $10,000, risk 1%, stop 20 pips on EURUSD: the copy is 0.50 lots, risking $100.
This rule needs a stop loss. See When the master trade has no stop loss.
Scale Master Lot by Equity. The master's lot times your equity divided by the master's equity. The slave then risks the same percentage as the master.
Master has $100,000 and trades 0.50 lots, slave has $10,000: the copy is 0.05 lots.
Minimum and maximum lot
- Minimum Allowed Lot: no copy is smaller than this.
- Maximum Allowed Lot: no copy is larger than this. A useful safety cap.
Results are rounded to the broker's lot step, usually 0.01.
When the size is below the minimum lot
A much smaller account copying small lots can work out below the broker's minimum. You choose what happens:
- Open at the minimum lot (default). The copy opens at the minimum, which risks more than intended.
- Don't copy the trade. The trade is skipped and the reason appears in Execution Errors.
Extra scaling for the multiplier
With Fixed Multiplier you can tick "Automatically scale lot size proportionally if Master Balance differs from Slave Balance". The copy is then also scaled by your equity compared with the master's.
Which rule should I use?
- Same account size as the master: Fixed Multiplier at 1.0.
- Different account sizes, same risk as the master: Scale Master Lot by Equity.
- A set risk per trade, whatever the master risks: Risk Percent.
- Testing, or a strict cap: Fixed Lot.