This depends on each particular project, and the team behind the project. Choosing a good ICO is absolutely necessary because it will determine whether you are profitable or losing money. First read about the white paper of the ICO project, see the value of altcoin on the site, learn about the project development team, if they are famous and well known, it will be very good and special it needs a clear blockchain. If there are separate cold storage, the better. You need to find out before you decide to invest, otherwise the risk of loss will be high