After the disaster, the finger-pointing begins. Scrutiny of the exchange-traded-fund industry has intensified since UBS announced a $2bn loss allegedly caused by one of its ETF traders.

In fact, worries about ETFs, listed funds that typically track an underlying index, already had been building among regulators, with both the Financial Stability Board and the Bank of England expressing concern. The UBS incident could prove a catalyst that turns concern into action.