Bitcoin's price has been manipulated with another cryptocurrency: tether, professor says

The analysis showed a pattern of bitcoin price support, Griffin said. First, tethers are created by Tether Ltd., often in large chunks such as 200 million coins. Almost all new coins then move to Bitfinex, he said. When bitcoin prices drop soon after the issuance, tethers at Bitfinex and other exchanges are used to buy bitcoin “in a coordinated way that drives the price,” Griffin said in an interview.