NEW YORK ( TheStreet) -- Don Dion posts his current insights on the stock, bond, commodity and currency markets in his RealMoney blog, anticipating which ETFs will be in play next. In the following three blogs from the past week, Don commented on gold ETFs, consumer staples and investing in Japan. Is Your Gold ETF Safe? Part 15/17/2010 12:14 p.m. EDT ETFs have become an increasingly popular way to gain exposure to gold, helping to transform this precious metal into an asset class in its own right. As more and more investors allocate assets to ETFs such as SPDR Gold Shares ( GLD) and iShares Comex Gold ( IAU), isn't it time to take a look at how safe these funds are? In Part 1 of this two-part blog, we'll take a look at the risks associated with physically backed gold ETFs. Part 2 will explore potential dangers in trading other gold ETFs available in the market today. Physically backed ETFs, which essentially offer investors exposure to a stockpile of physical metal, are the best-known of the bunch. SPDR Gold, the largest U.S.-listed physically-backed gold fund, also has the distinction of being the second-largest U.S. ETF. With over $48 billion in assets as of May 14, GLD is second only to the SPDR S&P 500 ETF ( SPY) -- an index fund that has a more-than-11-year head start. SPDR Gold, launched in 2004, tracks a physical stockpile of gold held for the fund in the form of allocated 400-ounce London Good Delivery Bars in the London vaults of HSBC Bank USA. Investors can visit the fund's Web site to see pictures of gold bars and view FAQs. According to the fund's site, "agreements among the Trustee, Bank of New York and the Custodian, HSBC USA NA allow for the Trustees to visit and inspect the Trust's holdings of gold held by the custodian twice a year. In addition, The Trust's independent auditors may audit the Gold holdings in the vault as part of their audit of the Financial Statements of the Trust." While "allow" and "require" are two very different words, investors should feel secure in allocating assets to this large, well-monitored fund. GLD's Web site allows investors to track the "gold bar list" of assets held for the fund, and the gold's central location may be comforting to some investors. The site also points out that the gold held for the fund is insured.