Its tempting to buy as it was listen on Poloniex, although i see it was launched 1-2 days ago on liqui. The ico was $24M and right now is $300m + m.cap. I would remember how gnosis was listen on polo the first day...
Ethfinex (by bitfinex) will use 0x protocol.
Bitfinex has 1 bn$ in volume last 24 hours.
Polo listing was merely a small jump, nothing compared to how it will go when ethfinex, distributed, openanx and many more decentralized exchanges launch and people start paying their fees by ZRX.