I can proove that with one very important thing: after the poloniex have announced that they are going to de-list all these 17 altcoins, the price have simply broken.
People were panic selling, basically most of the volume on the poloniex was being dumped, or in a good path to be dumped.
It is kind of funny, because some people are saying that poloniex have cheated their customers: but you need to remember that they would cheat, if these coins would pretty much dissapear, without doing de-list from the polo side.