I have some investments in bitcoin casino, i made 5-10% profit / month

Nice! 5%-10% is a good percentage and profit for a monthly basis with bitcoin casino's. And that is what I wanted to suggest, you can try to invest with bitdice.me
But the most effective and best way to invest in bitcoin is by just simply buying it at lower price which is quite hard to make it happen again.
The new low price for bitcoin will be at $1,000.