While little public information exists about how tethers are created, market pricing suggests traders believe that each coin is worth $1. Trading the token for Bitcoin at Bitfinex has helped drive up Bitcoin prices, Barry Leybovich, a product manager at IPC Systems Inc. who creates risk and compliance products for financial institutions interested in blockchain applications, said last month. A document on Tether’s website, compiled by accounting firm Friedman LLP, shows it had $443 million and 1,590 euros ($1,970) in bank accounts as of Sept. 15. Tether tokens were valued at $420 million that day, according to Coinmarketcap.com. Tether hasn’t identified the banks where that money was held, and their names were blacked out in the document.

https://www.bloomberg.com/news/articles/2018-01-30/crypto-exchange-bitfinex-tether-said-to-get-subpoenaed-by-cftc