IT was not very long ago that the dread hovering over global financial markets was that things were getting too calm. Just this summer, Federal Reserve officials were fretting over markets being so stable that it might create complacency, and we were writing about a global boom in asset prices. Even if many Americans do not fully realise it yet - though an unnerving drop in a wide range of global markets on Wednesday may have gotten our collective attention - the autumn has brought a rather darker set of worries with a series of dives in global financial markets.
On that day alone, the Standard & Poor's 500 briefly fell into negative territory for the year and the interest rate investors were...