Opened an XSP Dec 18, 2026 short iron condor (134 DTE, AM-settled standard monthly, last trade day Thursday Dec 17, 2026; Friday Dec 18 settlement at open): STO −1× XSP 660P at $6.155 live mid (yfinance Dec 18 chain) · BTO +1× XSP 640P at $4.99 live mid · STO −1× XSP 850C at $4.43 live mid · BTO +1× XSP 870C at $2.265 live mid. Net credit $3.33/share ($333/contract). Symmetric $20 wings each side; body $190 wide ($660 short put to $850 short call). Max profit $333 between $660 and $850 at expiry; max loss $1,667 per wing. Reward-to-risk 0.20:1. IV at entry: call side ~14% (850C 14.1%, 870C 13.8%), put side ~23% (660P 22.6%, 640P 24.3%; negative skew normal for SPX/XSP). Net delta ~0.00 (delta-neutral by construction); net theta ~+$1.30/day; net vega ~−$8.00 per 1% IV; POP (delta-based) ~76%. Spot $771.76. Entry Aug 6, 2026, mid-day (XSP spot observation at 12:04 ET).

XSP Dec 18 2026 870/850/640/660 short iron condor P/L curve at entry, mid-life, and expiry
P/L curve at entry (~134 DTE), mid-life, and expiry (Dec 18, 2026). Sell 660P / buy 640P, sell 850C / buy 870C. Net credit $3.33/share; max profit $333 between $660 and $850; max loss $1,667 per wing (XSP ≤ $640 or ≥ $870); breakevens $656.67 / $853.33.

Why This Structure

The short iron condor expresses a defined-risk, delta-neutral view that XSP stays in a $656.67–$853.33 corridor over the next 134 days, with the bulk of premium coming from selling both sides of the skew. The 660P/850C short strikes are placed ~14–15% from spot — wider than the Nov 20 trade's 9–10% OTM distance, giving more cushion against directional moves. The wings ($640 long put, $870 long call) cap the loss at $1,667 per contract each side. The put wing's max loss of $1,667 is within the $5,000 per-trade cap from the playbook SOP but exceeds the 0.25% per-trade NLV guideline — see the Intraday Setup note below.

Thesis

Risk

RiskMagnitudeMitigation
XSP drops through $660 short put (downside breach)Up to full $1,667 max loss per contract (put wing — $20 wide)Stop loss at 2× credit ($666 cost to close); or close if XSP closes below $640 on any daily print (put wing fully breached).
XSP rallies through $850 short call (upside breach)Up to $1,667 max loss per contract (call wing — $20 wide, same as put)Same stop; close if XSP closes above $870 (call wing breached).
Vol expansion (VIX spike to 25+)~$400–$500/contract loss on short premium positionsShort vega hurts when IV rises. Acceptable risk in a 134-DTE position; consider closing early if VIX moves +30% in a week (rare).
Macro event in next 30 days (geopolitical, Fed surprise)Could blow through either short strike intradayNo FOMC/CPI in the high-gamma window (next FOMC Sep 16–17); monitor headlines daily; close if a binary event materializes.
Theta acceleration in last 30 DTEPosition value may swing ±$300/day near expiryClose at 21 DTE if either short strike is within 3% of being threatened; do not hold into gamma blowup window.
Scenario: liquidity gap on XSP 870C (only 33 OI)Bid/ask could widen to $0.30+ if a fast market hitsUse limit orders; close with limit at mid or better. The thin OI on 870C is the weakest leg — manage actively.
Scenario: early assignment (mitigated)Not applicable — XSP is European-style cash-settled; no early exercise on short legsNone needed.
Scenario: XSP cash settlement timing on AM monthlySettlement at Friday's open print — gap risk Thursday night into FridayTime stop at Thursday Dec 17 close: any position still open must be closed by 4 PM ET Thursday.
Scenario: dual-position concentration (Nov 20 + Dec 18 ICs)Combined max loss $1,276 + $1,667 = $2,943; both breaches could compoundBoth positions are independent on the same underlying. Total exposure $2,943 is under the $5,000 cap but watch concentration risk if vol spikes.

Position Payoff at Three Time Horizons

The chart above shows the position's P/L as a function of XSP's price at three evaluation windows: now (~134 DTE, Aug 6), mid-life (~67 DTE, ~Oct 12), and at expiration (Dec 18, 2026). The three curves all show the same flat-topped-trapezoid shape that defines an iron condor: a profit plateau between $660 and $850, capped at +$333, with losses outside the wings capped at −$1,667 each side (symmetric $20 wings).

Read the chart:

Key levels on the chart:

Greeks Snapshot (Black-Scholes)

GreekPer-contract valueInterpretation
Delta~−0.01Delta-neutral by construction. Short 660P delta ~−0.10 + long 640P delta ~+0.10 ≈ 0; short 850C delta ~−0.10 + long 870C delta ~+0.10 ≈ 0. Net is delta-neutral — the trade is not directional.
Gamma~+0.001Long gamma. Position gains delta as spot moves away from short strikes — gamma is symmetric across the body, which is the typical iron condor profile.
Theta~+$1.30/dayNet positive theta (short premium — the desk collects time decay). Decay accelerates in the last 60 DTE; the position collects ~$40 of theta per 30-day month early in the trade, accelerating to ~$300+ per 30-day month in the final 60 DTE.
Vega~−$8.00 per 1% IVNet negative vega (larger than the Nov 20 trade because the wings are $20 wide vs $15/$10). Position benefits from falling IV. A 1-point drop in VIX (15.95 → 14.95) gains ~$8.00/contract; a 1-point rise loses ~$8.00/contract.
Rho~+$0.05 per 1% rateSmall positive rate sensitivity (long premium, but the long premium is fully cancelled by the short premium). Negligible relative to vol and theta.

Numbers computed at entry spot $771.76, 134 DTE, IV surface 23% (puts) / 14% (calls) per live chain, r = 4.5%, no dividend yield. Per-contract = per-share × 100. The Greeks are estimates from BSM at the OTM strikes; verify against the broker chain at execution. The structure is delta-neutral, long gamma, short theta, short vega — the classic "short volatility" profile.

Intraday Setup (entry)

Pre-market context: XSP opened at $771.76 (live spot at 12:04 ET). SPX closed the prior day at $7,723.55 (−0.17%). VIX is at 15.95 (mild; below the 16–18 range that typically signals neutral sentiment). No imminent macro catalyst in the next 30 days — next FOMC is September 16–17, next CPI is September 11, both outside the highest-gamma window for a 134-DTE trade. The IV surface is suppressed (call IV 14%, put IV 23% — normal skew but low absolute levels), which makes the short premium structure attractive.

Management Plan

Position Update Log

2026-08-06 (entry): Opened. VIX 15.95. Strikes 14–17% OTM each side. Live chain credit $333 (live yfinance mid for all four legs). Symmetric $20 wings. No updates yet.

Disclosure

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