Sam Bankman-Fried, founder of the FTX cryptocurrency exchange, has made a fortune in the industry. At the age of just 30, his net worth was estimated by Forbes magazine at US$24 billion. So he is not really someone you would expect to be casting doubt on the potential for a cryptocurrency to play a larger role in the global economy. But this month he did exactly that, telling the Financial Times that the energy required to mine bitcoin would limit its ability to grow. “It has to be the case that we don’t scale this up to the point where we’re spending 100 times as much eventually as we are today on energy costs for ... (full story)