The VIX Index measures the 30-day expected volatility of the S&P 500 Index. The components of the VIX Index areat- and out-of-the-money put and call options with more than 23 days and less than 37 days to a Friday SPXexpiration date. These include AM-settled SPX options with “standard” 3rd Friday expiration dates and PM-settled“weekly” SPX options that expire every Friday, except the 3rd Friday of each month2. Once each week, the SPXoptions used to calculate the VIX Index “roll” to new contract maturities. For example, on the day before VIXfutures and VIX options expiration, the VIX Index is generally calculated using two SPX option expirations: (1) oneexpiring 24 days later (i.e., “near-term”) and, (2) one expiring 31 days later (i.e., “next-term”). On the followingday, the SPX options that expire in 30 calendar days become the “near-term” options and the SPX options thatexpire a week later are “rolled” in as the “next-term” options.