I am of the opinion that , saving bitcoins is the best way to invest bitcoins ( Not when bitcoin price is above 850 - 900$ ) . It involves less risk according to me . If you ask me the best ways to invest bitcoins with greater risks ( with greater payouts ofc ) I will say
1. Investing in right crypto currency .
2. Investing in casino . ( not to gamble , to be the house ).
Investing in crypto is better in compare to investing it in casino as your money will be locked in casino but in crypto you can always sell when you see good amount of profits.
If you invest in a good casino and your money is not stolen by the operators, I think investing in Casino is a better option.