For more than a decade, huge fortunes have been made and lost in the world of cryptocurrency. While China has played a big role in the cryptocurrency boom, Beijing has been tightening its grip on the volatile market in recent years because of concerns it could disrupt the economy. Raymond Yeung, economist, and author of China’s Trump Card: Cryptocurrencies and its game changing role in Sino-US trade, says market volatility is only one reason state regulators do not view cryptocurrency as a legitimate form of payment.