First i apologies if this was discussed elsewhere, i made a quick search and failed to found a topic talking about it.
Well, I received an email from yobit, as a previous user of this shady exchange, where they mentioned that they will make a pump action.
I neglected it before reading it again where they stated that they will pump a coin with 1 btc each 1-2 minutes 10 times (total of 10 btc)... Best part is stating the possibility of loses and the no refund policy

(for more information :
https://mobile.twitter.com/YobitExchange)
Seriously, how could an exchange do this!! It is shameful. Wonder know if they do it also in secret.
Tl;dr : avoid this exchange.