Projects with such qualities will be very in demand in the future, if you think about the prospects, it is best to invest in such projects now.
Indeed, investments must be made in advance. After the excitement starts it is already very difficult to buy an asset at a bargain price.
I agree, especially for large investors. It is very difficult to buy a significant amount in a growing market. Usually it causes a big price increase.
Even if the market falls you will not be able to buy a significant amount of an asset on the exchange without much impact on the price. Therefore, investors participate in ICO.
Certainly, if there is a huge buy wall on any asset in an exchange will automatically affect price positively, in a way, this can only happens if you are investing a very large sum otherwise normal investors can just buy from exchange sometimes lower than ico.