The SPX Expiry Calendar
SPX has multiple expiration products with overlapping ticker structures. The distinctions matter — particularly AM vs PM settlement, which determines whether your position is exposed to overnight gap risk. The full calendar and what each contract type means in practice.
SPX options aren't a single product — they're a family of overlapping contracts with different tickers (SPX, SPXW), different settlement times (AM, PM), and different expiration cadences (monthly, weekly, daily). The distinctions matter most for the difference between AM- and PM-settlement, which determines whether your position carries overnight gap risk.
This article maps the full calendar and what each contract type means in practice.
The SPX and SPXW tickers
Two main option tickers on the S&P 500 index:
SPX — the original "monthly" expiration. Third Friday of every month, AM-settled. Has existed for decades.
The "weekly" (or non-monthly) SPX expiration ticker, used for all expirations that aren't the third-Friday monthly. Today SPXW covers Monday through Friday — the full daily-expiration cadence introduced progressively through the 2010s and completed in 2022. PM-settled (4:00pm ET close). Underlying is the same S&P 500 index level as SPX; only the expiration mechanics differ.
The two tickers represent the same underlying. The differences:
- Settlement timing: SPX (monthly) is AM-settled; SPXW (everything else) is PM-settled.
- Expiration cadence: monthly SPX expires once a month (third Friday); SPXW expires every weekday plus the same third-Friday date.
- Underlying calculation: identical — both reference the S&P 500 index level.
For 0DTE trading, the relevant product is SPXW. The monthly SPX still exists and is heavily traded, but its overnight-gap exposure makes it less popular for retail single-session strategies.
AM-settled vs PM-settled
The critical distinction between the two contract types.
A settlement mechanism where an option settles on the underlying's opening prints on expiration day, rather than the closing price. For SPX monthly options (third-Friday SPX), AM settlement uses the opening values of the S&P 500 components as they print Friday morning. The contracts stop trading at the close of the prior day (Thursday). Holders carry overnight risk between Thursday's close and Friday's open settlement.
The mechanics:
AM-settled (monthly SPX): contracts stop trading Thursday 4:00pm ET. Friday morning's opening prints determine the settlement value (computed from the index components' opens). The holder has no ability to manage the position between Thursday's last trade and Friday's settlement print.
PM-settled (SPXW, all daily/weekly): contracts trade through the regular session on expiration day, settling on the SPX 4:00pm closing value. The holder can manage the position right up until the 4:00pm close.
The weekly cadence
SPXW expirations across the week:
- Monday SPXW — daily expiration, PM-settled at 4:00pm.
- Tuesday SPXW — added by Cboe in 2022.
- Wednesday SPXW — daily expiration.
- Thursday SPXW — added by Cboe later in 2022, completing the weekday cadence.
- Friday SPXW — daily expiration. On the third Friday of the month, the monthly SPX (AM-settled) also expires on the same date — same calendar date, two different contracts.
Cboe completed the daily-expiration roster through 2022. Before that, SPX traders had monthly + Mon/Wed/Fri weeklies, with Tuesday and Thursday added during 2022. The full Mon-Fri cadence is what made the 0DTE retail trading explosion possible — every trading day became someone's 0DTE.
On a third Friday of the month, both products are available. Traders choosing 0DTE on that day usually pick the PM-settled SPXW rather than the AM-settled monthly SPX, even though both settle that day.
Monthly vs weekly vs daily — which to use
When each expiration type fits a trader's needs:
Daily (0DTE) — pure single-session exposure. All theta plays out in one day. All the 0DTE strategies in Module 5 use these. SPXW is the relevant ticker.
Weekly (1–7 days to expiration) — traditional short-dated trading with some time decay over multiple days. Used for short-dated credit spreads held over a few sessions, or for the longer leg of a calendar spread. SPXW for any non-monthly weekly.
Monthly (typically 30+ days) — longer-dated positions where per-day theta is modest and vega is meaningful. Traditional 30–45 DTE iron condors live here. SPXW for any monthly-equivalent expiration that isn't the AM-settled monthly SPX.
The AM-settled monthly SPX specifically — less commonly traded by retail today because the overnight gap exposure adds risk that the PM-settled SPXW doesn't have. The monthly is still actively used by institutional traders who want the AM-settled product specifically for index-hedging reasons. Most retail strategy traders default to SPXW for any expiration they want to trade.
For most retail 0DTE work, the simple rule: use SPXW. The monthly SPX exists but isn't typically the right tool unless you have a specific reason.
The expiration day timeline
What happens on a 0DTE SPXW expiration day:
- 9:30am ET: regular session opens. SPXW options trade through the day at quoted prices.
- During the day: standard options trading. Bid-ask spreads, gamma exposure, charm drift — all the dynamics covered in the 0DTE Dynamics module.
- 3:30pm: many retail traders close 0DTE positions to avoid the final-30-minute gamma exposure (covered in The Final 30 Minutes).
- 4:00pm: regular session close. SPX closing print is computed from the underlying components.
- Settlement processing: positions held to 4:00pm settle on that closing print. ITM cash-settled options pay the difference between SPX and the strike; OTM options expire worthless. Settlement appears in the account by the next morning.
Holiday and shortened-session considerations
A few calendar quirks worth knowing:
Market holidays. No SPXW on holidays (Thanksgiving Day, Christmas Day, etc.). The Cboe trading calendar publishes the year's schedule; check before assuming a daily expiration exists.
Shortened sessions. The day before some holidays is a half-session (1:00pm ET close instead of 4:00pm). On those days, SPXW expires at 1:00pm — settlement window moves earlier than usual. Worth verifying with your broker before trading.
Day-before-monthly issues. AM-settled monthly SPX stops trading at the prior day's close. A trader who hasn't traded AM-settled options before can be surprised when their position can't be closed Friday morning because trading ended Thursday afternoon. This is one of several reasons retail 0DTE traders typically avoid the AM-settled monthly entirely.
Practical reference checklist
Quick-reference for traders:
- For 0DTE strategies: use SPXW (the daily PM-settled expirations). Available Monday through Friday.
- Avoid holding AM-settled monthly SPX overnight unless you're explicitly comfortable with the gap risk. The overnight exposure isn't worth the cost for most retail single-session traders.
- Check the trading calendar around holidays for shortened sessions and no-trading days. The schedule shifts each year.
- Strike grids are identical for SPX and SPXW. Only the expiration mechanics differ. The IVs, deltas, and other greeks on the chain work the same way for both.
- For positions held into the close: settlement is based on the SPX 4:00pm closing print, computed from the index components' closing values. There's no separate options auction.
Key takeaways
- SPX options are a family, not a single product. SPX is the original AM-settled monthly (third Friday); SPXW is the PM-settled weekly/daily ticker covering Mon-Fri.
- The AM/PM settlement distinction is the critical one. AM-settled options stop trading the prior day and settle on the next morning's opening prints; PM-settled trade through expiration day and settle on the 4:00pm close.
- For 0DTE retail trading, use SPXW. The AM-settled monthly SPX adds overnight gap risk that the PM-settled SPXW doesn't have.
- Daily SPXW expirations cover Mon-Fri since 2022. Every weekday is someone's 0DTE.
- Settlement uses the SPX 4:00pm closing value — not a separate options-market auction. The closing print can move on individual ticks; settlement uncertainty is part of pin risk.