In terms of hold for a long term, there is no much risk (if the coin is listed on exchange and had a successful ICO), cause the rise in its price will come, just the matter of time. But when it comes to trading, there is risk of losses (day traders, more losses), cause when the bum comes, you are out (except you still have some good numbers of the coin). Holding is much more better, but one will still have to trade when the time comes.