I think for some reason bounty hunters dumping their token will somehow affect or will have a little effect at the trading price of certain tokens but i believe also another culprit is the bonuses given by the icos. I think if both the bonuses and bounty tokens sold at very low price then it's likely one of the reason that the price will be lower. That's why some of the icos delay the payment or they send the payment of the bounties batch after batch to prevent dump. As you know some of the hunters don't care about the project as long as they sold the tokens then they are out.