Investment is a Risk but we don't just invest in one thing without any background reading about it. We risk our money, because we know that our money will grow in our chosen coins/investment.
Risk is involved in every decision we take to some extent. This is due to the involvement of future. Future is unpredictable and anything can happen but present information can be used for mitigating the risk. But if a person is investing in bitcoin among crypto currencies, then there is no risk at all in my view.
The only problem he will face is to stay patient when there is a downfall. Though holders are supposed to increase their coins but they sell out most of the time during dip.