Cboe S&P 500 One-Week PutWrite Index (WPUT)
The Cboe S&P 500 One-Week PutWrite IndexSM (WPUT) is a variation of the PUT index. Like the PUT, WPUT sells and collaterizes an at-the-money put option on S&P 500 stock index (SPX put). This structure mimics a buywrite payoff and yields a buffered exposure to S&P 500® returns. While the PUT sells SPX puts monthly, WPUT sells an SPX put weekly. Another difference is that the Treasury bills are one-month bills only instead of one and three-month bills.
The WPUT portfolio is rebalanced weekly, typically on Fridays after the expiration of SPX options that expire weekly (SPX weekly options). SPX weekly options expire at the close, except on the third Friday of the month, when they expire at 11 am ET. A new weekly SPX put is then sold.