Module 1 · Options Levels Basics
Strikes, 0DTE & Daily Expirations
Why SPX has a zero-days option every single day.
In this lesson you'll
- Review strikes, calls and puts
- Define 0DTE
- Understand the SPX daily-expiration timeline
A call gives the right to buy at a fixed strike; a put gives the right to sell at the strike. The seller (writer) has the opposite obligation. Index options like SPX are cash-settled and European-style (exercised only at expiration), unlike SPY/QQQ (American-style, share-settled).
Why SPX has a 0DTE every trading day: Cboe added expirations over time — monthly, then Friday weeklys (2005), Monday/Wednesday (2016), and Tuesday & Thursday in 2022. With all five weekdays covered, every SPX session is now someone's expiration day. 0DTE has grown to roughly half of all SPX options volume.
Key takeaways
- Call = right to buy at the strike; put = right to sell; the seller takes the other side.
- SPX is cash-settled, European; SPY/QQQ are American, share-settled.
- 0DTE = an option expiring the same session.
- SPX has daily expirations (M–F since 2022), so a 0DTE exists every day — now ~half of SPX volume.
Check your understanding
Pick an answer to reveal instant feedback. Answer every question to complete the lesson.
Why that's off: It refers to time-to-expiry, not open interest.
Why that's off: 0DTE options still cost premium (often small).
Why that's off: Monthly options are the opposite end of the time spectrum.
0DTE = Zero Days To Expiration — an option expiring today. SPX now has daily expirations, so a 0DTE exists every trading day.
Why that's off: 0DTE is among the riskiest retail instruments.
Why that's off: Near expiry they can move enormously in percentage terms.
Why that's off: Nothing is guaranteed; total loss is common.
With ~no time left, premium decays fast (theta) and the option's delta is hyper-sensitive to price (max gamma). An OTM 0DTE can expire worthless within the session.
Educational content only. Nothing here is financial or trading advice. Order-flow and options patterns shift probabilities; they never guarantee outcomes.