Both Bitfinex and Tether, the company that issues the virtual currency, have been a cause of concern for some in the industry.
“The lack of transparency surrounding Tether raises red flags for me,” said Dan Ciotoli, software engineer and blockchain analyst at Bespoke Investment Group. “It’s probable that Tether issuance made significant contributions to artificially high bitcoin prices seen last year.”
Others have voiced concern that Tether doesn’t actually hold enough U.S. dollars to back all of its digital coins in circulation.
In December, the Commodity Futures Trading Commission sent a subpoena to Bitfinex and Tether. In 2016, the CFTC fined Bitfinex $75,000 for failing to register with the agency and offering “illegal” cryptocurrency transactions. A few months later, hackers stole 119,756 bitcoins from the Caribbean-based exchange.
Bitfinex is one of the largest cryptocurrency platforms in the world by trading volume, and while it is registered in the Caribbean and owned by a British Virgin Islands company, it also has offices in Asia and Europe.
Bitfinex CEO J.L. van der Velde told CNBC in an email that “Bitfinex nor Tether is, or has ever, engaged in any sort of market or price manipulation.”
“Tether issuances cannot be used to prop up the price of Bitcoin or any other coin/token on Bitfinex,” van der Velde said.
Tether did not respond to CNBC’s request for comment.
Griffin has spent the past decade publishing research on fraud by credit agencies, mortgage fraud by banks, to most recently manipulation of a volatility index known as the VIX.
For the time being, he’s turning his attention to the cryptocurrency market, which Griffin said has “not a lot of monitoring going on.”
“In general I research things that are potentially illegal, and there’s a lot of rumors surrounding potential questionable activity in cryptocurrencies,” he said. “That’s why it’s useful to see what the data says — data speaks.”