The iPath Series B S&P 500 VIX Mid-Term Futures ETN (VXZ) is a mutual fund that tracks the performance of the S&P 500 VIX Mid-Term Futures Index. This index measures the returns of a portfolio of mid-term VIX futures contracts, which are designed to provide exposure to market volatility. The fund is designed to provide investors with a way to potentially profit from market volatility, as well as to hedge against potential market downturns. As an exchange-traded note (ETN), it is a debt instrument issued by a financial institution and is subject to credit risk.