Trading volumes at major cryptocurrency exchanges fell by more than 40 percent in June, research showed on Monday, with a regulatory crackdown in China and lower volatility among the factors depressing activity.

Spot trading volumes fell 42.7 percent, to $2.7 trillion, with derivative volumes down 40.7 percent, to $3.2 trillion, London-based researcher CryptoCompare’s data showed.

“Headwinds continued as China persisted with its crackdown on bitcoin mining,” CryptoCompare said. “As a result of both lower prices and volatility, spot volumes decreased.”

Bitcoin, the largest cryptocurrency, fell more than 6 percent last month, touching its lowest since January, as authorities in China tightened restrictions launched a month earlier on bitcoin trading and mining.