You take a quick walk to the shops. You come back and the Dow’s down 1,000 points.

The volatility of the past week has been breathtaking. Last week, in an event now known as the ‘flash crash’, the Dow saw the biggest intra-day fall in its history.

Then on Monday, global stock markets enjoyed one of their biggest ever gains.

It’s all eerily reminiscent of late summer 2008, if you ask me. And we all know what happened next… Read on .