One of the big trends in options this year is the dramatic rise of trading in zero-daysto-expiry (0DTE) options . These are options that expire within 24 hours. Options\ that expire every day of the week are now available for popular securities like SPY and\ QQQ. According to the CBOE, 44% of the S&P500 option volume is for options with\ less than 24 hours to expiration, for a notional amount of over $500bn traded per day.\ The figure below lists prices and implied volatilities for puts and calls on SPY options\ as of the close on Friday, October 20, 2023. The middle column are the strikes, and\ the data on the left side are for the call options, and the data on the right side are for\ the put options. The first five rows are for options that expire the following Monday,\ one trading day later.