Loopring is an Ethereum-based decentralized exchange protocol with an automated execution. Loopring is not a decentralized exchange. It is an infrastructure that enables decentralized exchange. Loopring is designed to allow any platform that uses smart contracts to integrate. By pooling all orders sent to its network, Loopring provides maximum liquidity and optimal pricing across exchanges and platforms. One of Loopring's unique features is that users don't need to deposit funds with an exchange. Tokens remain in wallets and are not locked by orders. In addition to not requiring direct deposits, the protocol has innovative mechanisms built in that allow for a series of trades to be bound together in an order ring to fulfill each other. The orders can then be split through order sharing, where partial orders will be filled until the whole amount is completely filled. This unique automated execution feature increases liquidity.
Loopring wants to become a cross-blockhain protocol. It has plans to integrate with NEO and Qtum.

OKEx is a relatively new exchange that allows cryptocurrency investors to trade a wide variety of fiat and crytpo pairs. Although it is based in China, and caters to the Chinese market, it has a platform that is easy to use in all languages, and has quickly become one of the largest exchanges, by volume, in the world. The highly secure platform provides high liquidity, and has a number of other advantages.
OKEx has a user friendly interface that can be understood by all traders, regardless of their experience. Their platform is a good option for new crypto users because it supports trading of one of the widest varieties of different cryptocurrencies. It is also a good option for professional investors and day traders. They offer high trading limits, future contracts, and a number of other trading tools, including a block explorer.
Withdrawal Fee: 0.1% with a minimum of $15
Trading Fee: 0.2%

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.