An uneasy calm has settled over the market, with volatility back down to levels not seen since the tail end of the credit boom in 2007. Bulls are arguing that the decline reflects a return to stable economic growth, capable of boosting the value of assets, as an increasing number of investors decide the absence of risk can justify buying assets at higher and higher prices.

But Saltus Partners, an investment boutique led by former Goldman Sachs executive Simon Armstrong, is nervous. Its manager Dan Kemp points out that volatility lows can be followed by a sharp spike when complacency is blown apart by a nasty surprise.