You can't stop people from dumping coins especially people who got tokens in campaign. Company needs to have a decent plan on how to avoid their token getting dump but i think it's hard considering no one can easily manipulate the market. I had join some bounty campaigns that give their tokens in a weekly basis and some bounty hunters got furios because of it. Also it does not help because after each week that they gave the tokens. Someone will sell the tokens even below the price. If they want their token not to get dump. Development is the key to the success of the project.