5 BTC is not a big sum. You can HOLD them until next bubble and take profit , and then rebuy BTC  when the price falls,  you can invest in a bitcoin start-up - it can be  your ideea or u can google it,  or u can invest in some mining equipment.

Here is someone who have invested in his own ideea of an adult streaming site only in BTC: https://goo.gl/QSg6Gb
And here is someone who have invested in a mining farm : https://goo.gl/d4oXj6  ; https://goo.gl/dRsPHH
You can do something like this at a smaller scale.

You know that not all investments can give u profit, so u must have your eyes wide open when you make an investment.

Good luck!