An exchange-traded fund (or ETF) is essentially an investment vehicle with mutual fund features which trades on stock exchanges like a stock.  An ETF holds assets such as stocks or bonds and trades at approximately the same price as the net asset value (NAV) of its underlying assets over the course of the trading day.  As a result, an ETF investment provides the flexibility of a stock and the diversification of an index fund.  Recently, IndexIQ, a New York based investment firm, expanded the ETF universe when it launched the first ever U.S. hedge fund index-linked ETF in March, which offers the benefits of hedge fund investments to the public via ETFs, and then filed a registration statement for fifteen additional hedge fund replication ETFs in April 2009.  We review the filing, including a discussion of the advantages of hedge fund ETFs over actual hedge funds, and the relevant risk factors.