It's hard to say that the most dump after listing some from bounty hunters. But that's the truth. If you wanna avoid dump, better you invest in ICO that don't have a bounty program. The price usually more stable and have a chance to climb if they have a good product.
but maybe the ICO will not be known by many if there is no bounty campaign. maybe a small number of investors are bounty participants and the rest may be people outside the forum. I personally regret that a coin is dumped when listing a market, but if I sell it can might dump further again