A big question looms. We know that the coronavirus will spread, possibly infecting the majority of the global population in time. We know that the economic disruption it may cause has spooked every stock market in the world. And we know that in an effort to conquer the panic, the world’s most powerful policymakers have fired off “bazookas” by the bucketload.

What no one knows — after one of the worst ever weeks in financial markets — is whether Covid-19 will move from a health emergency and resultant market slump into a full-blown financial meltdown.

The last time there was this level of mayhem in the markets, banks such as Northern Rock and Bear Stearns were teetering on the brink of collapse. They turned out to be 2007’s harbingers of a far bigger disaster: by 2008 the global banking system had to be rescued, at a cost of hundreds of billions of dollars. The repercussions for politics and the economy can still be felt around the world.