For sure return per month either you need to learn to trade the market or you need to invest with someone who is already experienced and trading the market with consistent profit. You may set a profit percentage with that trader but before investing you amount anywhere a deep search needs to be done about the trader's profile. Some genuine investment firms trading currency market do an agreement for such return, even they provide post dated cheques for fix return if investor wants it, such investment  firms are giving 2% fixed return + variable, it means 2% return is fixed, if profit per month is more than 2% then it will be devided by 2. Ofcourse forex account will be on investor's name and he/she can monitor the progress with investor password.