The profit depends on the coefficient. It is calculated as the Investor’s funds divided by Trader’s equity:
Imagine that your Trader has equity of 100 USD and you invest 10 USD in his/her trading.
In that case, if their get 100 USD Profit (i.e. 100% of their equity) you will get a profit of 10 USD (i.e. 100% of your investment).
Thus, the coefficient of the invested amount/Trader’s equity here is 1/10, so the profit coefficient is also 1/10.
This way Trader's profit multiplied by the coefficient is the sum of your profit (100*0,1=10).
Investors can always add funds to deposit – in this case, the coefficient will be recalculated.