While exchange-traded funds are not losing their allure for investors, the market turmoil of the past summer has taken its toll. Synthetic ETFs, in particular, have come under pressure and some providers are no longer making them available to their retail clients.

In events reminiscent of the credit crisis of 2008/2009, several European banks have been downgraded over the past few months and the spreads on their credit default swaps widened dramatically for synthetic ETFs.