The price of bitcoin slipped back below the key $50,000 threshold on 13 May, after Tesla boss Elon Musk said the cryptocurrency was too energy intensive to accept as a form of payment.

Musk said bitcoin’s energy consumption “over the past few months is insane”, though he added that the company intends to keep the billions of dollars worth of bitcoin on its ledger and use it for transactions once bitcoin’s network is more sustainable.