The VSTOXX® Short-Term Futures Inverse Investable Index replicates the performance of a short position in constant-maturity one-month forward, one-month implied volatilities on the underlying EURO STOXX 50® Index. The index continuously rolls over on a daily basis from a short position in the first month VSTOXX Futures contract to a short position in the second month contract while taking into account the bid-ask spread in the roll procedure.