Even if you look at the most successful ICO's, there is always a selloff period once the token reaches the exchange. The price often falls greatly. However, in cases where the project succeeds or shows good signs of progress, there is often a return to a greater price than the ICO final price.
Therefore investing in ICO, it is very important to look at the importance of the project itself. Aside from that almost all tokens first fall sharply in price and, as a rule, are restored to the ICO price in about six to eight months. Of course, there are coins that do not recover at all, it all depends on the value and necessity of the project itself.