Well, what normally happens on most presales where I participated no matter what the discount during presale is that presalers usually sell when they gain profit. So what usually happens is that after some time price will eventually drop and that's normal. If you have ever bought some coins/tokens during the presale, and then the presalers dump, that's fine, as long as the project is a legitimate one. You can also add some in your bags and be thankful for the discount. Investing especially in projects with long term roadmap and unique utility are always worth holding. So don't stress yourself to much about what will happen a day after the presale.