Hey man,

Unfortunately there is no risk free way to invest your bitcoins and if there was that would not be the best of rewards at the end strictly speaking, the moment you brought into bitcoin you took a huge risk which shows you are either willing to take the risk or you never knew what the risk was.

Sounds like you are looking for a bitcoin bank and this you probably should not be doing within bitcoin we are own banks and our funds are our  funds they will not be loaned to someone else at interest so then you receive interest theu are just stored by yourself.

The best thing i can think of is you could loan btc out to people who have collateral, there is risk to it but not much if you always use collateral.

Good luck