0DTE

Also called Zero days to expiration, same-day options

Options that expire in today's session.

0DTE ("zero days to expiration") options expire in today's session. SPX lists an expiration every trading day, so there is always a 0DTE SPX contract; SPY and QQQ do too.

They have the most gamma and the fastest time decay of any expiration, so a small move swings their delta and value a lot. That's what draws traders to them, and why dealers' hedging of 0DTE positions can matter for the day's price.

In Theta Vantage

0DTE in the top bar's expiration set counts only today's expirations. On Pro every view uses it: the levels, exposure by strike, the heatmaps, the chart's levels. It's empty on a day without a session and after the last of today's expirations has expired.

Two cautions. Contracts opened today carry no open interest until tomorrow, so a 0DTE estimate misses the day's new positions, and 0DTE flow is traded heavily both ways, so the dealer side is the least certain of any expiration. Time to expiration is floored at one hour, so the last hour's gamma is an estimate held steady rather than one that runs off to infinity.