The minimum capital that is required to trade effectively and compound profit is 50$; anything below that means that you are literally wasting your own calls, signals; because without a good capital; the only way to make money is if you are making over 100% profit which is not sustainable. Your profit is someone else trade capital; so i implore us to twice your trading capital.
And once again, if you are to scared to loose money; then don't trade, it is not for you
I think even $50 is pretty less. I am coming from the fact that ordinarily few exchanges have minimum withdrawal limits on btc which would definitely not allow you to withdraw less than a certain amount so even if you make 10-20$ profits you won't be able to withdraw it. Moreover your monthly returns wouldn't be more than 30-40$ or something less than that so ideally this won't be a very profitable business vis-a-vis time you will need to invest in this business. I think 200$ is the minimum capital you would need to get atleast a graceful returns and that also if you live in a 3rd world country.