0DTE Options: How Same-Day Expiry Works
0DTE options are options with zero days to expiration: contracts that expire at the end of the trading day on which they are bought or sold. With hours rather than weeks left, their price reacts sharply to small moves in the underlying, and most of their time value is gone by the close.
A 0DTE option is not a new kind of contract. It is an ordinary option on the last day of its life. What changed is that there is now one of those last days every trading day.
How it works
Cboe defines them plainly: “0DTE (zero-days-to-expiry) options, sometimes referred to as ‘same day expiring’ options, are options contracts that expire at the end of the current trading day” (cboe.com, 0DTE resources page, read 25 Sep 2026).
Every option becomes a 0DTE option eventually. A monthly contract with three weeks left becomes a 0DTE option on its expiry morning. The term matters now because of how often that morning comes around.
An expiry every weekday
S&P 500 index options now expire every weekday. According to Cboe’s history of same-day trading (Spencer Doar, 3 Aug 2023), SPX Weeklys began with Friday expirations in 2005. Wednesday and Monday expirations were added in 2016, and the full Monday-to-Friday set was completed in 2022.
SPX options settle in cash. Cboe’s SPX page says positions “settle directly to cash at expiration” and that the options can only be exercised at expiration. There are no shares to deliver, and each point of the index is worth $100 per contract.
Time value is the part that disappears. An option’s price is what it would be worth if exercised now, plus extra for the time left. On the last day, that extra shrinks toward zero by the close. The rate of that shrinking is theta, and it is steepest in the final hours.
Small moves have large effects. Near expiry, an at-the-money option’s value swings sharply as the index crosses the strike. That sensitivity is gamma. Cboe’s own page warns that near-the-money options close to expiration “are extremely sensitive to movements in the underlying index.”
They are now most of the market. Cboe’s 0DTE page states that 59% of SPX volume traded 0DTE and 48% of XSP (Mini-SPX) volume, read 25 Sep 2026. Its 2 Sep 2025 post reported a record 62.4% share in August 2025, about 2.4 million contracts a day, with retail traders an estimated 53% of it.
A worked example
A hypothetical, with the arithmetic shown. Say the S&P 500 index sits at 7,600 on an expiry morning. A trader buys one call with a 7,610 strike that expires at today’s close, for $5.00. At $100 a point, that is $500 paid.
The break-even is the strike plus the premium: 7,610 plus 5 is 7,615. The index has to rise 15 points, about 0.20%, by the close just to get the $500 back, before commissions.
Now three possible closes:
- Index closes at 7,600, unchanged. The call is below its strike and expires worth nothing. All $500 is gone.
- Index closes at 7,615. The call is worth 5 points, or $500. The trader is back where they started.
- Index closes at 7,630. The call is worth 20 points, or $2,000, four times what was paid.
The asymmetry is the whole story. An unchanged day, which the rest of the market barely notices, costs this trader everything. A 0.20% rise only breaks even. The payoff only looks attractive on days that are unusual, and nothing in the example says how often those come. It is arithmetic, not a result or a forecast.
The original data
In the 24,971-video corpus this site studies, 22 videos have 0DTE in the title, from 18 channels. The median is 32,668 views, against 9,493 for the 1,061 videos with “option” or “options” in the title. Same-day options draw more than three times the median audience of options content in general.
What the video titles sell
What the titles sell is telling. 8 of the 22 titles contain the word “strategy.” The most-watched is a news report on the risks,, and one other title advertises an accuracy percentage. A title can promise a method; it cannot show what the method costs on the days it does not work.
Official data points the same way. Cboe’s figures above show same-day contracts are now most of SPX option trading. The corpus shows the explanations reaching viewers are mostly pitched as strategies. The gap between the two is where the basic mechanics on this page tend to get skipped.
When it fails
The first failure is the ordinary day. In the worked example the index finishes flat and the bought option loses its entire premium. A buyer needs an unusual day, and needs it before the close.
The second is the opposite trade. Selling same-day options collects small premiums on quiet days, but the loss on a sharp move can be many times the premium taken in. The size of the move that hurts is set by gamma, and near expiry it is at its most extreme.
A third is the frequency itself. With an expiry every weekday, there is always a contract available, so it is easy to trade daily without a reason. Five losses of a full premium in a week is a real week, not a bad scenario.
A fourth is sizing it like a longer-dated option. A same-day premium can go to zero in hours, so the amount paid is the amount at risk. Position sizing has to assume that outcome, not treat it as unlikely.
And a fifth is skipping the paperwork. The Options Clearing Corporation states that before buying or selling an option, investors must read the Characteristics and Risks of Standardized Options, and brokers must deliver it under SEC Rule 9b-1 (theocc.com, read 25 Sep 2026). The risk section applies with full force when the option has hours to live.
Related
Options expiry explains what happens at expiration, which for a 0DTE option is the same day. Theta covers the time decay that drains a same-day option by the close. And gamma explains why small moves in the index swing these options so hard in the final hours.
Decide the most you will pay before the session opens, and treat that premium as already spent. With a same-day option there is no tomorrow to wait for, so a plan made mid-move is usually a plan made by the move.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.