This happens very often my friend.Just someone who cleverly manipulate prices.I never advise anyone to sell coins immediately after receiving.There are of course exceptions but let them remain an exception
I think this is the result of false hope and pure hype. newbie investors often get tricked since they (we) don't have much experience to go by in comparing ICOs and doing proper research. Hopefully this announcement about a new ICO marketplace called Menlo.one will really help us tell the difference between good ICOs and those that we need to avoid.