For investors, world war one was a bolt from the blue – a crisis almost wholly unanticipated by stock markets until the first week of July 1914. By contrast, world war two was long foreseen by the markets, priced in from as early as 1936.

World war three was different again. As the nuclear arsenals of the superpowers grew ever larger, it became harder to imagine a life worth living after Armageddon; shorting the planet was not really an option.