Exchange-traded funds listed around the globe that invest in gold hold more than $1 trillion in total assets, as investors continue to move into metals ETFs to hedge against inflation and seek shelter from sovereign-debt uncertainty.

Gold ETFs added 45.6 metric tons of bullion, or 2.2%, in the second quarter, according to a report this week from the World Gold Council. Together, they now hold 2,155.3 metric tons of gold worth more than $1 trillion.

Collectively, gold-backed ETFs "had strong net inflows during the second quarter," according to the industry report. "ETFs have fully established themselves as an integral vehicle for accessing the gold market."

Outside the U.S., ETFs listed in Europe and India saw notable inflows last quarter.

SPDR Gold Shares (NYSE: GLD) is the largest U.S. gold ETF, with more than $60 billion in assets. Gold ETFs have followed futures prices to all-time highs this week. Other big U.S.-listed gold ETFs include iShares Comex Gold Trust (NYSE: IAU) and ETFS Physical Swiss Gold Shares (NYSE: SGOL)

"Activity in ETF options remains robust and continues to offer alternative strategies for investors," the World Gold Council said. "The majority of the volume in these products is still being transacted by way of GLD options."

Full disclosure: Tom Lydon's clients own GLD.

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