An exchange traded fund that holds gold bullion briefly wrestled away the title of the world’s largest ETF over the summer, before falling prices and investor outflows cut into the fund’s assets under management.

In August, SPDR Gold Shares (NYSEArca: GLD) surpassed SPDR S&P 500 (NYSEArca: SPY) as the biggest ETF by assets, with both funds holding over $70 billion at that time. [ETF Spotlight: SPDR Gold Shares (GLD) Becomes the Largest ETF]

Currently, the gold ETF houses about $64.5 billion in assets, compared with $97 billion in the S&P 500 ETF, which is back in the top slot. The stock fund is the oldest U.S.-listed ETF, having launched in early 1993.

For the gold ETF to retake the title, it will need a rebound in gold prices and renewed investor interest.

Gold prices, along with ETFs that track them, hit record highs in 2011 as safe-haven investors flocked to the precious metal in the late summer months when the markets were at their most volatile. While gold has been losing strength since reaching its lofty highs, some analysts say the fundamental factors backing the precious metal remain strong. [Can Gold ETFs Push to a New Record High in 2012?]

Goldman Sachs projects gold prices will end the year at $1,940 an ounce, or a little higher than the $1,925.10 high in early September 2011, reports Mike Obel for the International Business Times.

Separately, Deustche Bank told its clients that markets in the middle of a commodity super-cycle and gold prices will continue to draw support from negative real interest rates. [Gold ETFs Try to Regain 200-Day Average]

“Our strongest conviction trade remains long precious metals and specifically gold,” Deutsche Bank wrote in a recent note. “In an environment where real interest rates are negative and the U.S. equity risk premium is high we expect this will sustain strong private and public sector demand for gold.”