I have noticed that good ICOs also dump after listing, competing with crap ones that have no definite direction, but to cart away funds.
There are ways in which they can be protected and prevent unreasonable dump in price. Some of which are:
1. They should be managed by credible and trusted managers, managers that already have good reputation on the forum, else the trust might not be there.
2. KYC should be made mandatory for all bounty and airdrop participants in order to avoid multiple accounts. The kyc should be announced
3. Participants should be made to complete the remaining process of their registrations on the project's website, where IP can be detected. Multiple accounts can also be prevented this way.
4. Listing should be done on reliable and reputable exchange sites.
5. There should be regular and prompt communication with the community.
6. Projects should maintain and comply to their roadmaps and if there is amendment, the community should be made to know, with concrete reasons.
Additional suggestion:
7. An approach that will create the demand for tokens, which can as well prevent dump, is the lockup of certain percentage of the tokens.
Some percentage of the tokens belonging to; the team, advisors, investors, promoters and bounty participants.
The main tokens for the investors should be released, at least to compensate them for the money invested, but their bonuses should be locked for certain period of time. Which is followed by their gradual release.
These are just few among so many other solutions, but if this few are integrated into the system, i believe dump can be minimized if not totally eliminated.
I want to tackle 4 as well, listing on well known exchanges has little impact on your project value, so do not be deceived.
What matters most is the product we are talking about.
Pundi x listed in binance poloniex and others, and it did nothing to increase their worth