As I have noticed these days, when the ICO hasnt finished yet and the sale was still on going, the bounty tokens has already been distributed and also unlocked they sell it immediately on forkdelta or etherdelta for a much lower that ICO price, in which it could greatly disturb the sales in tokens. As for you the investor on that token, would you panic when you see that the tokens you own already selling at much lower price?
Dumpers are part of this business I guess so if you involve yourself with crypto world without knowing all the risk that may arise with being an investor then I guess the natural reaction for value deppreciation of assets would be unpleasant and you tend to panic for sure. As for me I have also tried investing in an ico but I know in myself that there's this certain risk that I may encounter with my capital so I'm already prepared with unfortune event that may occur with my investment. I would not panic but of course I will feel slightly sad but since I have the patience to wait then I will just hold my assets and patiently wait for the perfect timing to sell.