anyone trading this yet... In related news, Barclays Bank PLC debuted the iPath S&P 500 VIX Short-Term Futures ETN (NYSE Arca: VXX) and the iPath S&P 500 VIX Mid-Term Futures ETN (NYSE Arca: VXZ). Both VIX ETNs provide investors with exposure to one or more maturities of futures contracts on the CBOE Volatility Index which reflects the implied volatility of the S&P 500 Index at various points along the volatility forward curve. ETNs are debt instruments linked to the performance an index. ETNs, unlike ETFs, carry credit issuer risk similar to the risk of investing in individual bonds. VXX is designed to track the S&P 500 VIX Short-Term Futures Index TR which targets a constant weighted average future maturity of one month. In contrast, VXZ is designed to track the S&P 500 VIX Mid-Term Futures Index TR which targets a constant weighted average futures maturity of five months.