When using the “Fixed Lot” method, whatever the Master trade size is, each trade placed on the Slave account will use the defined value as the trade size, no matter the Equity, Balance or Free Margin of both Slave and Master accounts.
Below the formula used to compute the slave order size:
The “Fixed Lot” value could be any positive or negative value, the system will round up to the closest volume incremental step for the traded instrument. A negative value will reverse the order side.
If the minimum order size allowed by your broker for a specific symbol is bigger than the lot size computed, the Trade Copier copies the min trade size. In this particular case, the system always tries to copy the trade with the minimum allowed value.
Please note that if you are using a broker account configured with mini, micro or standard lot, settings a "Fixed Lot" with a value of 1, will open respectively 1 mini, 1 micro or 1 standard lot.