As crypto traders watched their portfolios deteriorate Wednesday, Turkish-born American economist Nouriel Roubini took to social media to reiterate his stance on cryptocurrencies and blockchain, the decentralised technology that underpins them.

Roubini, who famously predicted the collapse in the US housing market and banking system, has been just as bearish on digital currencies since they began their meteoric rise in 2017. In February, he said bitcoin was going to zero and has called bitcoin “the mother of all bubbles,” living up to his “Dr Doom” nickname.