In an attempt to understand the relatively new but wildly popular Exchange Traded Funds (ETFs), Dr. Bogan did extensive research into the structures used by ETF operators, with a special focus on the potential risks that might arise should they be faced with large and sudden liquidations. Given that there are about 2,000 ETFs in existence, with assets totaling over $1 trillion, we thought it appropriate to find out what Dr. Bogan has learned in his research.