Skip to content

Summary

0DTE (zero days to expiration) structures are verticals and iron condors opened and typically resolved within the same trading session, dominated by SPX and SPY options which list expirations every weekday1. The same spread mechanics from Vertical Spreads apply, but the timescale compresses every greek: theta is consumed intraday in hours, gamma dominates by the afternoon, and vega is nearly irrelevant. This concept is a modern extension of the book-derived toolkit and is held at draft status pending verification.

Construction

  • Same-day verticals: short-delta credit spreads (bull put or bear call) struck at a morning-move distance from spot, sized by the day's opening range and expected 1-day move.
  • Same-day iron condor: both credit verticals placed roughly one expected intraday standard deviation out; profit zone is the entire remaining session inside the strikes.
  • Typical workflow: enter after the first 30–60 minutes once the opening auction range is established; manage or close before the final hour when gamma risk peaks.

Payoff Table

Short 0DTE iron condor on SPX — short put below, short call above, credit C:

SPX at close P&L
Between short strikes +C (full credit)
Beyond a short strike C − (distance beyond strike), floored at max loss = −(width − C)
Through a wing Max loss

Unlike 30–45 DTE structures there is no meaningful interim "meander" phase: the position transitions from theta harvest to directional/gamma bet within hours.

Greeks Profile (vs. 30–45 DTE baseline)

Greek 30–45 DTE credit spread 0DTE equivalent
Theta Positive, spread across weeks Positive but fully consumed by close — decay is front-loaded into the session
Gamma Modest; grows into expiry week Very high all session; explodes as spot approaches a short strike
Vega Meaningful negative Near zero — there is no remaining life to reprice
Delta Small, drifts Large per unit of move; probabilities re-rate in minutes

The vega collapse is the key difference: a 0DTE short premium trade is a bet on today's realized path only, not on implied volatility mean-reversion4.

Best Regime / Market View

  • Flat-to-gently-trending sessions where the opening range holds; the seller is paid for the day's unrealized movement.
  • Auction dynamics matter: overnight gap, opening imbalance, and morning order flow set the expected move; the Cboe-listed daily expirations concentrate liquidity in the morning and final-hour auctions1.
  • Poor fit on event days (CPI, FOMC) unless run as a post-announcement intraday structure.

Primary Risks

  • Gap and trend risk: a single impulse move can carry spot through a short strike with no time to repair; max loss arrives faster than adjustment logic.
  • Gamma near the strike: pin and flip risk in the final hour is extreme; short strikes that were 1 SD out in the morning can be at-the-money by 2 PM.
  • Assignment/settlement mechanics: daily/weekly SPXW 0DTE series settle PM, against the 4:00 PM closing value; only the designated classic monthly SPX series settle AM against the opening print. SPX is cash-settled and European-style, while SPY is American-style with share assignment — the two products carry different operational tails1.
  • Liquidation and slippage into the close as market makers pull quotes on expiring strikes.
  • Crowding/flow effects in 0DTE volumes are still being studied; the empirical literature is young (hence draft status)2.

Management Levers

  • Take-profit early (e.g., 50–75% of credit by midday) rather than holding the theta lottery to the close.
  • Hard time-stop: close or flatten by a fixed clock time, since late-day gamma is unhedgeable at reasonable cost.
  • Close the tested side as a single vertical rather than adjusting the whole structure.
  • Position size by full width of the spread — the 0DTE loss tail is compressed but not absent.

Variants

  • Post-event 0DTE: enter after an afternoon announcement (FOMC) once the move is visible — a pure momentum-continuation structure.
  • 0DTE iron fly: maximum credit if the close pins the body; extreme pin risk.
  • Broken-wing 0DTE: skew the wings against the overnight gap direction.
  • Delta-lean opening verticals: debit spreads with the morning trend instead of mean-reversion credit.

References

  • Cboe Global Markets, "0DTE Options" education pages, cboe.com — daily expirations on SPX, volume/liquidity context1.
  • M. Staunton, "Zero DTE", Wilmott magazine (Wiley, 2023) — quantitative profile of same-day options2.
  • S. Passarelli, Trading Option Greeks, 2nd ed. (Wiley, 2012) — baseline spread and greeks mechanics3.
  • D. Chen & M. Sebastian, The Option Trader's Hedge Fund (Pearson, 2012) — the 30–60 DTE credit-spread baseline these structures compress4.

Links

Source Notes

  1. Cboe 0DTE options education resource, https://www.cboe.com/education/. ↩↩↩↩

  2. Staunton's Wilmott analysis of zero-DTE trading; verify exact issue/year before promotion to stable. ↩↩

  3. ../trading-option-greeks/topics/spreads.md. ↩

  4. ../option-traders-hedge-fund-bundle/topics/strategies.md. ↩↩