Definitely hold... if you sell imediately you will earn a very small amount and if you hold you will have the chance to earn a whole lot more...
if you do a bounty, this means you believe in the project (or should mean), so you should hold
so, unless you are into pumps&dumps, if you have a global approach and hold, the amount you will get on the projects that became successfull will largely overcome the amount you supposedly loose on the projects that fail, and also overcome the value you would get if you sell immediately
cheers