In May, I wrote a column that warned that the fast-growing world of exchange traded funds was heading for a scandal. To be honest, my expected timeline was years, not months.

But history is playing out faster than I guessed. We do not yet know precisely what has gone wrong at UBS; and, in particular, with the conduct of Kweku Adoboli, the ETF trader. But when regulators eventually unpick this $2bn mess, I would hazard that one culprit will turn out to be a pernicious cocktail of opacity, complexity and naive enthusiasm for innovation.

For what has happened in the ETF world in recent years has some uncanny echoes of what took place with collateralised debt products last decade; and the fact that it was those CDOs which caused such terrible damage for UBS in 2007 just reinforces the historical echoes. And the bitter irony.