Not so long ago, volatility traders were relishing the prospect of Donald Trump’s presidency. A volatile personality prone to explosive outbursts and erratic behaviour, he could send markets soaring or crashing with a single late-night tweet. A rollercoaster ride seemed assured. But in the six months since his inauguration, the markets have been eerily calm. The S&P 500 has inched its way to an all-time high and implied volatility – measured by the Vix – is at a historic low.