As sure as night follows day, the rapid growth of the Exchange-Traded Funds movement is leading to an increase in the number of attacks being made on its credibility, as investors and regulators fret over the way an ETF snafu could disrupt the capital markets.

Paul Tucker, deputy governor of the Bank of England and Terry Smith, chief executive of money broker Tullett Prebon, each launched broadsides this week. Their attacks follow criticism of derivatives-fuelled ETFs mounted by the Financial Stability Board, Bank of International Settlements and International Monetary Fund, who all saw the need for greater transparency.