Ethfinex is a cryptocurrency exchange focused on ERC20 compatible tokens that was created by Bitfinex. It aims to be, not only a trading platform, but also a community discussion platform for ERC20 compatible tokens and ethereum-based ICOs.

Ethfinex is a hybrid decentralized exchange. Traders can choose between trustless on-chain settlement, or high speed centralized execution. By using decentralized remote portals, users can access the Ethfinex order book without actually having to deposit their funds with Ethfinex. Ethfinex also has a robust API, remote portals, and margin trading.

Ethfinex wants to be a hub for the overall ERC20 token community. It is a good option for those looking to trade tokens, but it also a platform that can be used by Ethereum developers for their crowd-sourcing needs.

Ethfinex has a user-friendly interface but it is primarily designed for intermediate and advanced traders. It offers margin trading, a crowdfunding funding market, and an active discussion forum about ERC-20 projects. It has a wide range of order types available, including the basic market, limit and stop loss orders.

Ethfinex has a variety of security features, such as cold wallets that require multiple managers to unlock. There are also a number of automatic verification tools in place, and 2-factor authentication is encouraged for all accounts.
Ethfinex features its own token, the Nectar tokens (NEC). NEC tokens are given for free to token market makers in proportion to the volume of trades they participate in on the exchange.

Trading Fees: Tiered system depending on volume ranging from 0.1%-025%

CEX.io is a British company that changed its focus from mining into becoming a cryptocurrency exchange. CEX has made an effort to add many coins, and boasts of fill-or-kill (FOK) orders that allow for some of the industry’s fastest trading, but it has a poor record on privacy and transparency that should give pause to traders.
The exchange’s fill-or-kill (FOK) orders are very fast, but come at a steep 7% fee. The mobile application is easy to use, and there is also an API integration. CEX is a regulated exchange that complies with all KYC and ALM laws, so they are able to accommodate several funding options, including credit cards and bank transfers.
The majority of CEX.io’s trading volume is done with bitcoin, and although they have made an effort to add more coins, this exchange simply does not have the trading options that others do. The low trading volume of other major coins provides limited liquidity for most traders.
Trading fees vary depending on trading volume between 0.16%-0.25%.Bank transfers are free and withdrawal fees are lower compared to their competitors, but transfers can take up to 20 days.
Although CEX.io is easy to use and allows for very fast crypto purchases, it has high fees, delayed withdrawal times, and a poor record on privacy/transparency.