It depends on the coin that you are talking about, some of them get dumped on the market as soon as they are released, but it also depends on how the market is going and how the project is being managed, and of course, what people thinks about that one
there is no different. ICO project is only a blockchain startup. 99,99% of them have no product to offer and create a value.
it is just a promise that they will build a powerfull apps or anything else. if they fail, the value of that coin or token will going to zero.