Mechanics · SPX 0DTE · verified 2026-09-25
Can you get assigned on SPX 0DTE? (2026)
Not in the share sense. SPX/SPXW options are European-style and cash-settled: no early assignment, no shares delivered. A short contract in the money at the 4:00pm ET close is debited intrinsic value × 100 per contract the next business day. SPY and QQQ options differ — American-style, physically settled, assignable any day and by exception at $0.01 at expiration.
Instrument facts last verified 2026-09-25 · broker rows last verified 2026-09-25
Written and verified by the 0dteclose desk · methodology · corrections: corrections@0dteclose.com
Run it on your own position
See what 4:00 does to your SPX strike
Prefilled with a 7700 call bought at 2.40 — enter your own strike and price; the readout uses the 15-min delayed CBOE quote.
| Fact | Value | Source |
|---|---|---|
| Settlement | Cash, to the official S&P 500 closing value on expiration day (PM-settled SPXW) | www.cboe.com verified 2026-09-25 |
| Exercise style | European — exercisable only at expiration; no early assignment | www.cboe.com verified 2026-09-25 |
| Multiplier | 100 (intrinsic value × 100 per contract) | www.cboe.com verified 2026-09-25 |
| Last trade, expiring contract (ET) | 4:00pm ET (1:00pm ET on early-close sessions) | www.cboe.com verified 2026-09-25 |
| Auto-exercise threshold | Not applicable in the share sense — any in-the-money amount is settled in cash, no shares | www.cboe.com verified 2026-09-25 |
| OCC exercise-instruction cutoff | Not applicable — no exercise decision; the 4:00pm ET closing value is final | www.optionseducation.org verified 2026-09-25 |
| Exercise / settlement reference time | 4:00pm ET official closing value; OCC closing marks use the 4:00pm ET NBBO | www.cboe.com verified 2026-09-25 |
| Cash settlement posts | Next business day (T+1) | www.optionseducation.org verified 2026-09-25 |
Can an SPX option be assigned before expiration?
No. SPX and SPXW options are European-style, which means they can be exercised only at expiration, so a short SPX position cannot be assigned early — not on the day before an ex-dividend date, not after a large intraday move, not ever before the expiration close. For a 0DTE contract the question comes down to one moment: the official S&P 500 closing value at 4:00pm ET on expiration day. At that point OCC settles every in-the-money SPXW contract in cash. The short side does not receive an assignment notice for shares; it receives a cash debit equal to intrinsic value × 100 per contract, posted the next business day. This is the main mechanical difference from SPY and QQQ options, where a short position can be assigned on any business day and assignment means 100 shares per contract changing hands at the strike. Arithmetic, not advice: what you do with that difference is your decision.
What time does trading in the expiring SPXW contract stop?
Cboe's SPX/SPXW specification says trading in SPXW options will ordinarily cease on the day of expiration at 4:00pm ET, so an expiring SPX 0DTE contract stops trading at 4:00pm ET — the same minute its settlement value is fixed. Cboe's extended-hours FAQ puts it the same way: expiring SPXW PM-settled index options stop trading at 4:00pm ET because they are European-style and cash-settled. That is 15 minutes earlier than expiring SPY and QQQ options, which trade until 4:15pm ET. There is no after-hours window in which a late move can change an SPXW result, and no exercise decision to send in after the bell. On early-close sessions, such as the day after Thanksgiving, both the session and the settlement move to 1:00pm ET, and the countdown on the SPX simulator follows the NYSE calendar. Standard third-Friday SPX monthlies are a different product: they are AM-settled to an opening value, and nothing on this page applies to them.
How is the settlement value determined?
A PM-settled SPXW contract settles to the official S&P 500 closing value on expiration day. That value is computed from the closing prices of the 500 component stocks, not from the last index print on a chart, so it can differ from the last-traded value by a few cents — our session archive records the close for every session with the source field named. Intrinsic value is plain arithmetic: for a call, settlement value minus strike; for a put, strike minus settlement value; zero if the result is negative. Multiply by the 100 multiplier for dollars per contract. Worked example: a 7700 call with the index closing at 7712.35 has an intrinsic value of 12.35, which is $1,235 per contract. If the index closes at 7699.99, the same call is out of the money by one cent and settles at $0 — there is no partial credit and no threshold to clear beyond the strike itself.
What exactly hits my account, and when?
For a short SPXW contract that finishes in the money: a cash debit of intrinsic value × 100 per contract, settled the next business day. Worked example — sold one 7700 call at 2.40, collecting $240; the index closes at 7712.35, so intrinsic value is 12.35 and the debit is $1,235, a net $995 per contract before commissions and fees. Short an 7700 put in the same session and it expires worthless, so the $240 premium stays. Until the debit posts, the broker keeps the position's margin requirement in place, which is why buying power can look reduced the evening of expiration. No stock position appears, no short shares are created, and there is nothing to cover the next morning. The same numbers for a long position — credited instead of debited — are on what happens if my SPX 0DTE expires in the money, and the SPX simulator runs them for your own strike and price.
What if I'm short the contract?
Being short an SPXW contract into the close means accepting a cash debit that is set entirely by the 4:00pm ET closing value, with nothing after that able to change it. There is no after-hours window for a holder to exercise against you, no $0.01 exercise-by-exception question, and no do-not-exercise instruction on either side, because settlement is automatic and in cash. The maximum debit on a naked short call is open-ended — every point above the strike adds $100 per contract — while a short put's debit is capped only by the index reaching zero, so the broker holds margin against it until settlement. After 4:00pm ET the expiring contract no longer trades, so it cannot be closed; before 4:00pm ET it can be bought back in the market like any option. The session archive shows how far the SPX close has landed from the 3:30pm ET price on recent sessions, dated and sourced.
Does my broker do anything on its own?
With SPXW there is nothing to deliver, so the broker policies that exist to stop an account from receiving shares it cannot pay for rarely come into play. What a broker can still do is close a position before 4:00pm ET when the account would breach its margin requirement at settlement — the table below records each broker's published policy, and tastytrade and Interactive Brokers both describe risk-team or simulation-based closing on expiration day. The exercise cutoffs brokers publish (Robinhood 5:00pm ET, Charles Schwab (thinkorswim) not confirmed from an official page, tastytrade 4:30pm ET, Interactive Brokers 5:25pm ET, Webull 4:00pm ET) govern instructions on physically settled options such as SPY; for SPXW the 4:00pm ET closing value decides everything and no instruction changes it. Rows we could not confirm on an official page carry an unverified badge; the per-broker tracker has the full record for each broker, dated.
How is this different from SPY/QQQ?
Four differences, all mechanical. First, settlement: SPX pays cash; SPY and QQQ deliver 100 shares per contract at the strike. Second, style: SPXW is European, so it cannot be exercised or assigned before expiration; SPY and QQQ options are American and can be assigned on any business day. Third, time: an expiring SPXW contract stops trading at 4:00pm ET, while SPY and QQQ options trade until 4:15pm ET and holders can send exercise instructions until their broker's cutoff (OCC's own is 5:30pm ET). Fourth, the threshold: SPY and QQQ contracts in the money by $0.01 or more at the 4:00pm ET close are exercised automatically, turning a long 650 SPY call into a $65,000 share purchase. Tax treatment differs too — SPX options are Section 1256 contracts; the §1256 calculator shows the 60/40 arithmetic next to SPY's short-term treatment.
What about a spread?
Each leg settles on its own, in cash, and the amounts net in your account. Take a 7700/7710 call spread, long the 7700 and short the 7710. If the index closes at 7725.00, both legs are in the money: the long leg is credited 25.00 × 100 = $2,500 and the short leg is debited 15.00 × 100 = $1,500, a net $1,000 — the spread's full width × 100, which is its maximum value. If the index closes at 7704.00, only the long leg is in the money: $400 credited, the short leg expires worthless. If it closes below 7700, both legs expire worthless. Because nothing is delivered, SPXW spreads carry no pin risk in the share sense: a close between the strikes cannot leave you holding stock over the weekend. The 4:00pm ET closing value decides both legs at once, and nothing after that changes them.
Broker by broker
| Broker | Exercise / do-not-exercise cutoff (ET) | Unaffordable ITM position at expiration | Cash-account settlement | Source |
|---|---|---|---|---|
| Robinhood | 17:00 ET (best-efforts; app/web exercise requests close 4:00pm ET) | May attempt to sell the option in the market within the last 30 minutes before close on expiration day if the account lacks buying power/shares to exercise; if unsellable, may submit a Do-Not-Exercise request to the OCC so the contract expires worthless. | T+1 | robinhood.com verified 2026-09-25 |
| Charles Schwab (thinkorswim) unverified | unverified | Per Schwab's expiration guide: if a long option is ITM at expiration and the account cannot support the resulting position, the brokerage may at its discretion issue a do-not-exercise instruction on the client's behalf, or close out (sell) the position without notifying the client. Schwab's own exercise-instruction cutoff time is not stated on the page (OCC's is 4:30pm CT). | T+1 | www.schwab.com verified 2026-09-25 |
| tastytrade | 16:30 ET (3:30pm CT) for exercise / do-not-exercise requests via the Trade Desk; best-efforts until 17:30 ET (4:30pm CT) | Risk team may close an option position before the market close on expiration day if the account is subject to expiration risk (an exercise/assignment that would create a large unhedged position). Sell-to-open orders on expiring equity/ETF options are prohibited in the last 30 minutes of trading. Do-not-exercise / exercise-by-exception requests must reach tastytrade by 3:30pm CT. | T+1 for stocks, ETFs and options; cash accounts day-trade only with settled funds (Good Faith Violation rules apply) | support.tastytrade.com verified 2026-09-25 |
| Interactive Brokers | 17:25 ET — IBKR must receive exercise / lapse requests for US-listed equity options by 5:25pm ET (Option Exercise window or Message Center ticket); exercises and lapses are irrevocable | IBKR simulates expiration under plausible price scenarios; accounts projected to violate margin after settlement may face liquidation of expiring positions on the last trade date, lapsing (non-exercise) of long ITM options, immediate liquidation of underlying positions subject to delivery, and closing-only restrictions. | T+1 (US options: one day) | www.interactivebrokers.com verified 2026-09-25 |
| Webull | 16:00 ET (market close) | Webull Financial LLC reserves the right to close any options position that poses a risk if exercised or assigned, but is not obligated to act — position management remains the account holder's responsibility. | T+1 (next business day for trades placed before 8:00pm ET) | www.webull.com verified 2026-09-25 |
Quick answers
Can SPX options be assigned early?
No. SPX and SPXW options are European-style: exercise happens only at expiration, so there is no early assignment.
Do I have to deliver shares if my short SPX 0DTE call expires in the money?
No. It is cash-settled: intrinsic value × 100 per contract is debited the next business day. A 7700 call with a 7712.35 close is debited $1,235.
What time is the SPX 0DTE settlement value fixed?
At the 4:00pm ET close: the official S&P 500 closing value on expiration day. Expiring SPXW contracts stop trading at 4:00pm ET.
Can someone exercise against my short SPX option after the close?
No. There is no after-hours exercise decision for SPXW; unlike SPY and QQQ (OCC cutoff 5:30pm ET), the 4:00pm ET closing value is final.
How is SPY assignment different?
SPY options are American-style and physically settled: assignable on any business day, and at expiration anything in the money by $0.01 or more at the 4:00pm ET close is exercised by exception — 100 shares per contract at the strike, settled T+1.
Related
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- SPX vs SPY tax §1256 60/40 arithmetic
- SPX spread settlement both legs in cash, worked table
- Missed the exercise cutoff? OCC 5:30pm ET vs broker windows
- Broker tracker cutoffs and policies, dated
- How much can you lose? max loss by position type
- Methodology sources and limits
Expiration-rule changes, by email
One email when a broker or exchange changes an expiration rule we track. Nothing else.