Iit had to end sooner or later. In the run-up to Christmas, while everyone was making a few last-minute purchases, the longest bull market recorded in history ended quietly.

There was no spectacular crash or panic, but as prices moved inexorably down, markets ended up with their worst December performance since 1931, and the S & P 500 benchmark index was officially in a bear market at the end of the month a 20pc drop from its high. So also the tech-heavy Nasdaq, the Nikkei in Tokyo and the German Dax.

Shares have since revived a touch of buoyancy, though weak trade between Christmas and New Year, when most people do not sit at their desks, means little. It could…