In 2017 ICOs have massively gained popularity. Reports claim that over 5.6 billion USD have been raised through the run up in ICOs in 2017. The pre-sale simply marks one specific stage of an ICO procedure. 

All investors participating in an ICO are getting cheaper prices as expected opening prices on the first exchange launch. Nevertheless all attendees of a pre-sale are getting even bigger discounts. The pre-sale is taking place before the ICO procedure and can be risky as the proper ICO guidelines and prices might not be fully cleared. Therefore increased risk is getting covered by additional discounts.