https://en.wikipedia.org/wiki/Bitfinex
https://www.bitfinex.com/
While opinions are common and truth is hated, I will say it one more time.
Bitfinex and Tether are a collusionary scam, and you should avoid them, protest against them, and put them out of business by not participating in anything that deals with them.
Unless you're a crooked pump and dumper who only wants profits. If you only want profits, then create your own mini-market ( there are now more than TEN THOUSAND of them, create your own worthless idiot coin, give yourself 40 million of them, trade them on your exchange for something valuable, like say Bitcoin, and the cash out, ripping off everyone in the process and completely puking all over the concept. There. You're now a Swedish rip off artist that owns two companies.
* Make sure you create a bunch of shell and parent companies with pretend addresses in places like Gibraltar.