When the news broke last week that Elon Musk, the chief executive of Tesla and SpaceX and the world’s richest man, had paid US$2.9 billion (£2.3 billion) for 9.2 percent of Twitter, the media world – old and new – briefly lost what might loosely be called its collective mind. What was Musk up to? (He’s always up to something, after all, even if it’s just trolling.

On 8 February, Elon Musk’s electric-car firm Tesla announced that it had invested US$1.5 billion of its cash reserves in Bitcoin back in January. The news helped to boost the cryptocurrency’s already skyrocketing price by a further 10 percent, to a record high of more than US$44,000. But, especially in Bitcoin’s case, what goes up can just as easily come crashing down. Bitcoin was invented in 2008 and began trading in 2009.