Are investors growing leery of the equities market? In a possible sign of skittishness, the $30.2 billion SPDR Gold Shares (GLD) fund rose 1.3% in the past week as the $169 billion SPDR S&P 500 (SPY) lost 5% in a broad stock sell-off. Now investors seeking to diversify portfolios with commodities have a new choice: an ETF described as the first to provide long-only, broad exposure to the asset class in a 1940 Act structure.