Bitfinex is one of the largest exchanges
Ethfinex is created by Bitfinex in partnership with 0x
they are creating token based decentralized exchange with the underlined coin Nectar token (NEC),
more of the exchanges are getting pressed by the governments, and soon we will migrate from centralized and regulated exchanges, this looks very promising because of 0x (great project ) and bitfinex already being an exchange,
I recommend you check it out at https://www.bitfinex.com/ethfinex
or read the whitepaper https://www.bitfinex.com/ethfinex-whitepaper.pdf
thank you for reading and keep0n.steemin