GLD Challenging SPY For ETF Crown

Not surprisingly, gold's recent ascent amid a weak market where investors' confidence in other asset classes has been shaken has been a boon for ETFs backed by holdings of physical gold, namely the SPDR Gold Shares (NYSE:

). For years, GLD has been the second-largest ETF in the world by assets behind the SPRD S&P 500 Trust (NYSE:

). SPY can also lay claim to being the first ETF introduced in the U.S. and while it will always be able to brag about that, SPY's days as the world's biggest ETF appear numbered. At the end of July, SPY had roughly $27 billion more in assets under management than GLD, but SPY has seen its AUM haul plunge from $93.3 billion at the end of last month to $73.8 billion at the end of last week, according to State Street Global Advisors, the sponsor of both GLD and SPY. GLD had about $72 billion in AUM at the end of last week, State Street said. At the end of July, the third-largest U.S.-listed ETF was the Vanguard MSCI Emerging Markets ETF (NYSE:

) with less than $50 billion in AUM, so SPY and GLD don't have to be looking over their shoulders worrying about VWO quite yet.