So, is the Bitfinex BTC/USD market now a USD or USDT market? The price premium compared to other exchanges indicates it's a BTC/USDT market yet it's called BTC/

So, is the Bitfinex BTC/USD market now a USD or USDT market? The price premium compared to other exchanges indicates it's a BTC/USDT market yet it's called BTC/USD. Has anyone sold BTC on bitfinex? Do you get USDT or USD?