Coronavirus. That will be the first and last time this column mentions that word. Despite the weekend's many developments in the epidemic, there is a new issue to drive the markets. Like the dreaded disease, its effect is to take an already disquieting market trend and make it far more extreme. The breakdown of the OPEC talks in Vienna on Friday, followed by Saudi Arabia's announcement that it would abandon attempts to limit supply, and instead aim to increase market share, has driven a historic fall in the oil price.
With Brent and West Texas Intermediate crude both down more than 20% when trading began in Asia, this was on course to be the worst day for the oil price since January 1991, when a coalition was fighting Iraq over its invasion of Kuwait:
Moves this dramatic can create quite a shock. This could be good news for beleaguered airlines, whose fuel will be much cheaper, and it should provide a broad economic stimulus as motorists and industrialists see fuel costs reduced. But those benefits take time to make themselves felt.