So many factors play rule in the price after listing a new project,
First: The one who get the token as bounty some if not to say all will sell the token because it became a tradition that the price will dump after listing,even if they believe in project they will dump and buy again in low price.
Second: Some investors get the token in private sale with low price and bonus, and if the private-sale token is not lock by the team, know that token will dump.
Third: Team member may sell and dump the price because they need fast cash and do not care about project they are developing.
Of everything you say is true and with all that we cannot do anything except by seeing what happens when the price drops. For point 1, it often happens and for point 2, every sale must have a bonus. And for point 3 the project team actually didn't do that, but there were also those who did it.