You cannot tell that which token value will increase or decrease. I use to sell the token when it get listed on low or high profit as i know that it will come down surely and that time i use to buy back the tokens i sold with the profit and then keep it for long term. As their will always selling pressure from bounty hunters and ico investors , as almost all bounty hunters use to sell the coins and mint the btc and same some ICO investors use to sell the coins in low profit also. So that is the time when the price of the coin goes down and it is right time to buy back and if the project is good then buy back in low and keep for long term. and sell as and when you feel it good to sell.