The liberation of finance is one of the most significant transformations brought about by today's era of globalisation. The scale of cross-border flows, the extent of financial innovation and the size of the fortunes made in financial activities are among the most noteworthy features of our age. Yet the survival of unchained financial capitalism cannot be taken for granted. It will endure only if a sizeable portion of humanity decides that it serves their interests. That is far from certain, as the current backlash against private equity, on both sides of the Atlantic, demonstrates.

The explosion of financial activity is remarkable. According to the McKinsey Global Institute, the ratio of global financial assets to world output soared from 109 per cent in 1980 to 316 per cent in 2005. The value of the global stock of equities and bonds reached about $140,000bn by the latter year. On top of this mountain is piled yet another, made of derivatives, whose face value reached $286,000bn in 2006, up from a mere $3,450bn in 1990.