Bitfinex is one of the world’s biggest Bitcoin exchange by volume.
Bitfinex is technically an all-crypto exchange at current.
Bitfinex does, however, support Tether (USDT), the quasi-fiat token unofficially pegged to the US dollar’s price. Indeed, Bitfinex is a major shareholder in Tether and is probably the majority holder of these coins.
Bitfinex features an advanced, customizable GUI, over 50 trading pairs (e.g. BTC/ETH), and plentiful order types, such as limit, market, stop, stop-limit, trailing stop, fill or kill, and scaled orders.