> there is no market for BTC/USDT on Bitfinex as far as I can tell
You have it backwards. There is no BTC/USD market on Bitfinex. Their "BTC/USD" market is a BTC/Tether market. They have simply labeled it wrong to mislead people. USD cannot be deposited or withdrawn from Bitfinex, only Tether, and that makes their "USD" market a Tether market no matter what the ticker says.
It's really a brilliant scam, but it's only a matter of time before Tether is shut down for enabling money laundering, and Bitfinex with it. Banning US citizens may buy them a little time but it won't last forever. Bitfinex will be the next BTC-e, only worse. Not only is their volume higher than BTC-e, they may bring down Bittrex and Poloniex with them.
You have it backwards. There is no BTC/USD market on Bitfinex. Their "BTC/USD" market is a BTC/Tether market. They have simply labeled it wrong to mislead people. USD cannot be deposited or withdrawn from Bitfinex, only Tether, and that makes their "USD" market a Tether market no matter what the ticker says.
It's really a brilliant scam, but it's only a matter of time before Tether is shut down for enabling money laundering, and Bitfinex with it. Banning US citizens may buy them a little time but it won't last forever. Bitfinex will be the next BTC-e, only worse. Not only is their volume higher than BTC-e, they may bring down Bittrex and Poloniex with them.