5% monthly is huge. In the Europe, the bank interest is less than 1% per year.
Don't look for the bank for this kind of thing since surely they will just give you a little profit from your money but instead look for decent business where you can earn the most their so many alternative their where you can actually earn that and the thing you should bare is critical thingking,budget and etc and so by that maybe you can earn for huge percentage of profits by the time your business will be success. Investment on online matter is so risky if we would truly trust them for this and we will be lucky for that if we earn 2-5% a month.
Banks are just for savings nothing else more if people could think they could earn more with that well their pressumption is Very wrong since the sad truth is bank can offer us only 1% annual profits and that could be bad if we want to invest and multiply our money for certain period of time and might very better for this is to put our money in certain usefull programs like lending or tradings and their you can earn reasonable percentage of profits you desired.