My basic understanding behind why the value of crypto coins during ICO or IEO different from that of its value when it is listed on an exchange platform is that, during ICO, the team behind the project usually want the general public to invest in their project with the hope of them making some reason profits out of their investments. Usually, the value of the project coin is given a low value to get a lot of people to invest in it. For the actually value of the coin when it is listed on an exchange platform, its determined by the demand and supply of coin and its working project. If the project is really significant, the value of its crypto coin also gains the public attention causing either a raise or decrease..