Imagine the ramifications of a revolution in Saudi Arabia, the world’s largest producer of oil. Would the price of crude stop rising beyond $100 per barrel? Or how about a combination of events which trigger alarm in the €2.1tn Italian sovereign bond market: say, the collapse of Matteo Renzi’s administration while 600,000 people are evacuated from the shadow of a rumbling Vesuvius.

No matter how unlikely such scenarios may seem, for professional investors it is essential to play a version of this what-if game as they decide where to allocate their money in 2016. There may be opportunity but do not forget to assess the risks.

Some are quotidian: will a company struggle to generate cash flow, or will a particular asset — forestry land, retail stocks, impressionist art — fall into or out of vogue.