Before I sell my coins I'd do some research look for potentials if the coins are worth holding for. Technically,that's the right thing to do wait for the price to be more than the ico price before selling. And buys back when the price is on its dip price when its has a possibility to moon in the future..
Honestly, for me holding coins for months are okay but if you needed the money for some reason you sell, but if that money is kust an extra money then HODL it for as long as you want.