If I think that project is really good and has potential, I will hold all of tokens. Otherwise, I sell them immediately and buy a good coin in top 20 on CoinMarketCap
before you make sure that the coin is good or not, you should convince yourself before joining the project from the start. after you get the token from the bounty campaign you can wait for it to be registered on the exchange market. the problem of selling or holding assets that you own is your personal right.