The best option for now is hold Bitcoin. However it sis also can't be called toally risk free.
If you want something risk free, then buy some commodity that will cost more in the long-time future.
Actually there is really no a risk free investment in any form of business out there. You should always keep on mind that you would need to take the risk and take action for you to earn. Holding is a best option to earn but you could possibly try other things like investment and trading you could lessen the risk and have a multiple way of earning at a time. Through this you could earn more and have a higher possibility to earn rather than to lose on your investments or tradings.