Although I think this might not be the rule, on most ICOs I've seen in 2018/late 2017, there is a massive price drop just after the ICO and a huge opportunity to buy coin at prices way bellow the best ICO prices... this is indeed a very good opportunity for some people to buy more, but there is also the huge ICO problem that is trust... more than 90% of the ICOs are scams of some type (or failed at birth), so you can search and search and in the end, no matter how much experience you have, there will be a few fake ICOs on your way...
One of the reasons for the price drop is exactly the hunters and such that do not trust the project and dump all they have for a few bucks