Depends on how good the project you are investing in is good and how much buzz it created. For instance some ICOs don't allow people to buy from specific countries some of those being USA for instance. So when coins get listed on exchanges some people who are interested but were not able to buy during ICO will want to buy. On the other hand you will see that many people, like yourself will try to dump their tokens right from the moment they receive them. You can create sell order on ether delta and see where it goes. Possible scenario is that there are not simply enough buy orders to fill your sell orders if you have bought to many coins during an ICO so you could even sell your coins below the price you bought in the first place. If you do however believe in project simply let your coins because it takes time for devs to develop their platform and for your coins to be worth much more once other people start to use that platform.