Last Thursday morning investors queued around the block to buy the bonds of recent defaulter Greece, and by the end of the day were selling U.S. tech stocks furiously. In an investment world so used to the concept of 'risk on' or 'risk off' over recent turbulent years, the behaviour was puzzling. So what happened? Observers point to a combination of three drivers - stocks valued too highly, global growth failing to meet expectations and underlying investor behaviour since the turn of the year - but curiously no single catalyst. Many stock markets around the world, including those in both developed and emerging ... (full story)