Having gone through one of the toughest Decembers in history, the last thing investors may want to hear is that there are takeaways for their investing strategies for next year. Yet, if they ignore them, not only will investors risk feeling even more unsettled in 2019 but find themselves badly positioned to seize opportunities that will inevitably arise.

Global stock markets have been hit hard by a slowing world economy, less support from central banks and trade concerns. Since its recent high in late September, the MSCI World index has fallen some 15 per cent in highly volatile trading, including this week’s wild swings.

A brief glance backwards helps explain the challenge investors now face. In 2017 virtually all asset classes made money, even some that historically rarely did so at the same time. This happened in the context of unusually low volatility. Or, to put it another way, the three factors that investors look to balance — expected returns, variance (volatility) and covariance (correlations) — all broke in their favour to deliver a dream year.