Bitfinex is a Hong Kong-based cryptocurrency exchange. It was originally launched in 2014. You can trade 13 cryptocurrencies for USD and BTC: Bcash, Dash, Ethereum, Zcash, Monero, Litecoin, Ethereum Classic, OmiseGo, EOS, IOTA, Sentiment, Ripple and lately, they have added many new cryptos. Trading fees vary from 0.1% to 0.8% and you can simply trade with USD, with $20 least fee.
Registration and verification usually take 15-20 business days to proceed. And after that you will be able to start trading cryptocurrencies freely, enjoying professional instruments.