To maximize your profits on investment, it would be better to HODL and wait until the prices are more rewarding. Selling immediately would bring lower profits as you'll be competing with the bounty hunters.
I waited for several months already but i can see that their value are not getting any better, just up and down. If up it is still not as it was expected. Actually i already have a collections of ICO tokens and havent sold from any of them. 