where i can invest my btc and i can get a good profit ...with minimum risk? 
Well I'm sure there are services that offer buying actual stocks with bitcoin, that kind of investment is kinda safer than gambling and ponzi schemes.if any of those services are a legitimate stock broker who won't run away with my investments and also if they guarantee a minimal profit then i will invest in their service without hesitation.
And if they've been a stock broker for several years already and not just a fly by night company that hired a developer to make the website as appealing as possible.