for poloniex thats what i think
i think yes its scam they said i they are under dddos attack but i dont believe that at all , when the site stop and get back price are changed a lot
bittrex everything is normal
but there is a thing that this coins market can be bumped & unfair trade if someone or a groupe with big capitale invest in that
be careful guys thos sites arent confirmed even accepted by the any goverement so the can disapear anytime and take all your coin away and they can blame on hacks or something else
sorry guys for my english i wish that everyone gt my point here