I think that just keeping bitcoin for a long time now is the wisest act. The price fluctuates very much, so it's better to wait for a significant price increase. If you don't want to take any risky of investing it anywhere then its best to save your bitcoins for future by keeping them safe in your wallet as price is tend to rise in long term but make sure that you manage to hold enough amount of bitcoins as lower amount will not give you higher benefits.