Scan: Strait of Hormuz traffic returns to normal by October 31?

date	predicted	market price	confidence
2026-09-02	5%	10%	72%
2026-08-24	11%	16%	73%
2026-08-17	18%	22%	62%

1. Planner Fable 5.1 · Fermi decomposition + tool plan

Tools chosen: polymarket_direct polymarket_related kalshi_related article_search claude_news gdelt_news wikipedia code_execution

Sub-questions (Fermi decomposition)

What is the most recent IMF Portwatch 7-day moving average of transit calls for the Strait of Hormuz, and what has its trajectory been over the past 2-4 weeks?
What event caused the current drop in Hormuz traffic (Iranian closure/attacks, US-Israel-Iran conflict, mining, blockade), and is the disruption still actively enforced?
Are there active ceasefire, negotiation, or de-escalation processes with realistic timelines before October 31, 2026 that would allow shipping to resume?
What was the pre-disruption baseline of daily transit calls (~100-140/day historically), and how quickly did traffic rebound to 60+ after prior disruptions such as the June 2025 Israel-Iran war?
What are shipowners, insurers (war-risk premiums), and major tanker operators saying about resuming Hormuz transits, and are any already returning?
How does Polymarket price related Hormuz/Iran markets (e.g., closure duration, ceasefire, other thresholds) and does Kalshi have a comparable market that disagrees?

Planner reasoning

Resolution hinges on a hard numeric threshold (7-day MA of Portwatch transit calls >= 60) within ~11 weeks, so the key drivers are the current level and slope of Hormuz traffic, the nature and status of the underlying disruption (military/political), and the plausibility of de-escalation before Oct 31. Market price is the primary anchor; news tools establish the current shipping situation and diplomatic trajectory; historical recovery speed after prior Hormuz disruptions provides a base rate.

2. Research Parallel tool calls

tool	status	time	items	summary
polymarket_direct	OK	0.3s	1	## This Market's Polymarket Data Strait of Hormuz traffic returns to normal by October 31? - Current price (probability): 8.50% - 7-day price change: -1.00% - 30-day price change: -12.00% - Total volume: $608,086 (USD notional) - Price range: 5.50% - 22.50% - Data points: 32 days
polymarket_related	OK	1.9s	12	Scanned 100 active Polymarket markets, kept 12 matches. keyword 'Hormuz': 3 markets \| keyword 'Iran': 6 markets \| keyword 'ceasefire': 0 markets \| keyword 'Portwatch': 3 markets
kalshi_related	OK	1.8s	0	0 related markets / summaries. keyword 'Hormuz': no matches \| keyword 'Iran': no matches \| keyword 'Strait': no matches
article_search	OK	0.8s	23	Fetched 23 unique articles across 4 queries (lookback=45d). 'Strait of Hormuz shipping traffic tanker transits': 10 articles \| 'Iran Strait of Hormuz closure blockade': 10 articles \| 'Hormuz ceasefire negotiations Iran US': 10 articles \| 'IMF Portwatch Hormuz transit calls': 10 articles
claude_news	OK	29.5s	17	## Findings: Strait of Hormuz Traffic Status (as of early September 2026) - Origin/cause of disruption: The onset of U.S. and Israeli military operations against Iran in late February 2026 triggered Iranian retaliations, including Iranian efforts to assert control over the Strait of Hormuz via
gdelt_news	OK	205.2s	10	GDELT: 10 articles across 3 queries (lookback=30d). 'Strait of Hormuz tankers transit': error GDELT rate-limited after retries (429) \| 'Hormuz reopen shipping': error GDELT rate-limited after retries (429) \| 'Iran Hormuz mines navy': 10 hits
wikipedia	OK	0.1s	3	Fetched 3 Wikipedia entries (0 missing pages).
code_execution	OK	35.7s	0	## Model Results: Strait of Hormuz Traffic Recovery to 60/day by Oct 31 Setup: Baseline = 100–140 calls/day (mid 120); suppressed current level = 20/day (placeholder); target = 60/day (7‑day MA), i.e., need to close 40% of the baseline-current gap. **Ramp-up time needed (from a reopening decis

3. Evidence Brief Sonnet 5 · 7319 chars

# Current state The Strait of Hormuz remains effectively closed to normal commercial traffic: IMF PortWatch/tracker data show only ~5–13 transits/day as of early-mid September 2026, versus a pre-war baseline of ~100–130/day — far below the 60/day (7-day MA) threshold this market requires. Resolution is purely mechanical (PortWatch data hitting ≥60), not a political/media judgment of "normalcy." # Timeline of key events - 2026-02-28: US-Israel strikes kill Iranian officials, war begins (confirmed — Wikipedia). - Late 2026-03: Iran blocks/claims sovereignty over the Strait, begins attacking transiting vessels (confirmed — Wikipedia). - 2026-04-08: Two-week ceasefire begins; strains quickly (confirmed — Wikipedia). - Mid-April 2026: Islamabad talks fail; US imposes naval blockade on Iran (confirmed — Wikipedia). - 2026-06-17: US-Iran memorandum signed, lifting dual blockade (confirmed — Wikipedia). - 2026-06-28: US-Iran agree to halt attacks (confirmed — Wikipedia). - 2026-07-08: Ceasefire/MOU collapses after Iran attacks commercial vessels; US strikes ~90 targets in Iran (confirmed — Wikipedia/Insurance Business). - 2026-07-13–19: Traffic averages ~10/day (reported — Statista). - 2026-08-04–07: Bessent signals possible deal for "freedom of movement"; Iran publishes draft plan to ban US/Israeli ships and toll others; Iran-Oman negotiate transit-route framework (reported — CNBC, NPR). - 2026-08-12: Traffic near 3-month low, ~13 vessels/5-day avg (reported — CNBC/Kpler). - 2026-08-18: Gulf states reroute VLCCs via Oman; Iran loses effective control (reported — CNN). - 2026-08-25: US/Iran/Oman reportedly agree to clear mines (reported — multiple outlets: gCaptain, Al-Monitor, NY Post). - 2026-08-27: Tanker attack kills crew member; only 5 crossings that day (reported — CNBC). - 2026-08-28: CENTCOM confirms shipping lanes cleared of Iranian mines (reported — multiple outlets). - 2026-09-06/10: PortWatch records 6 transits (9/6); tracker (straits.live) reports Strait still "closed to commercial shipping," war-risk premiums ~40x normal, crisis index "extreme" (reported). # Event Will IMF PortWatch's 7-day moving average of Strait of Hormuz transit calls reach ≥60 on any date before October 31, 2026? # Outcomes to forecast - Yes (traffic normalizes to ≥60 7-day MA transits by Oct 31, 2026) - No (never reaches 60 in that window) # Kalshi market anchor No kalshi_direct tool output was returned in this research pass — a significant gap. The only directly matching market-ticker data available comes from polymarket_direct: current YES price 8.5%, down from ~22.5% high, 7-day change -1pt, 30-day change -12pts, on $608K volume across 32 days — a clear downtrend reflecting worsening on-the-ground conditions. Treat this as the best available proxy anchor pending confirmed Kalshi pricing. # Sub-question answers 1. **Recent PortWatch average/trajectory**: ~6 transits on 2026-09-06 (straits.live), down from ~85–130/day pre-crisis; 5-day avg ~13 on 2026-08-12 (CNBC/Kpler); brief uptick to ~25/day late June-early July, then falling to ~10/day mid-July. Trend has been volatile but consistently far below 60. 2. **Cause/status of disruption**: US-Israel strikes (2026-02-28) triggered Iranian blockade, mining, and vessel attacks asserting sovereignty over the Strait; disruption remains actively enforced — latest attack killed a crew member on 2026-08-27, and Iran's "Persian Gulf Strait Authority" still requires registration/routing (CNN, Wikipedia). 3. **Ceasefire/negotiation prospects**: Multiple ceasefires (April 8, June 17-28) collapsed within weeks; an August Iran-Oman mine-clearing/corridor framework emerged but hasn't restored traffic; CENTCOM claims mines cleared (Aug 28) but crew-safety concerns persist (S&P Global). No durable framework in place as of Sept 2026. 4. **Baseline/rebound comparison**: Pre-war baseline ~100–130/day (multiple sources). Unlike the 2025 Twelve-Day Israel-Iran war (resolved via ceasefire in 12 days with no reported Hormuz closure), the 2026 conflict has persisted ~7 months with repeated ceasefire failures — no comparable rapid rebound precedent exists this time. 5. **Industry/insurer signals**: War-risk premiums surged from 0.25% to as high as 10% of hull value, still ~40x normal by September; S&P Global says crew/cargo/vessel safety, not insurance, is the binding constraint on resumption — indicating shipowners remain unwilling even if cover is available. 6. **Cross-market pricing**: Polymarket prices earlier/related deadlines even lower — Sept 15 "return to normal" at 0.25%, Sept 30 at 1.7%, Dec 31 at 18.5% — showing markets see recovery as a 2027+ story at best. No comparable Kalshi market found (0 matches). # Key facts (high-confidence, factual) 1. [straits.live, CNN, CNBC] Transits ~5–13/day vs. ~85–130/day baseline as of Aug-Sept 2026. 2. [CRS/Congress.gov] Disruption has persisted ~7 months as of report date; likely continues while US/Iran can bear costs. 3. [Wikipedia] Two prior ceasefires (April, June-July) both collapsed within weeks. 4. [Insurance Business] War-risk premiums remain 6x-40x normal. 5. [gCaptain/CENTCOM] Mines reportedly cleared late August, but traffic didn't meaningfully recover afterward. # Cross-market signals - Kalshi related: none found (0 matches for Hormuz/Iran/Strait). - Polymarket (same-ticker): 8.5% YES, falling from 22.5% high, -12pts/30d. - Polymarket related: Sept 15 normal-return 0.25%; Sept 30 1.7%; Dec 31 18.5%; US-Iran ceasefire-continues 85.5%; blockade-end-by-Sept30 19.5%. # Analyst opinions and speculation - S&P Global (Kapoor): crew/cargo safety, not insurance, is the binding constraint — implies slow psychological/operational recovery even after formal de-escalation. - code_execution model: blended probability estimate ~25-50% (central ~38%) for reaching 60/day by Oct 31, contingent heavily on whether/when a durable reopening decision occurs (assumed 30-60% base rate) — but this pre-dates the confirmed Sept-level collapse to single digits, likely overstating probability. # Directional lean per outcome - **Yes**: Requires an abrupt, durable ceasefire/reopening plus rapid ramp-up (exponential recovery could hit 60 within ~1-3 weeks of a real reopening) — theoretically feasible with ~7 weeks remaining, but no current trigger evident. - **No**: Dominant — active hostilities, repeated ceasefire failures, extreme war-risk premiums, crew safety concerns, and current single-digit transit levels all point strongly to continued sub-60 traffic through Oct 31. Polymarket pricing (8.5% and falling) and steep decline from 22.5% support this. # Gaps / unknowns - No confirmed Kalshi YES price was retrieved in this research pass (critical gap vs. instructions). - No PortWatch data point later than ~Sept 10 was available to confirm trend into October. - Uncertain whether mine-clearing (late Aug) or Iran-Oman framework produces a genuine traffic uptick not yet reflected in data. # Calibration anchors - Polymarket YES 8.5% (proxy anchor, Kalshi price unavailable). - Related Polymarket deadlines: Sept 15 (0.25%), Sept 30 (1.7%), Dec 31 (18.5%) — showing monotonic but still-low probability even by year-end. - Precedent: 7 months of unresolved conflict with two failed ceasefires argues against rapid normalization within remaining ~7 weeks.

4. Forecasters Fable 5.1 + GPT-5.6 Sol · in parallel

claude-fable-5-1

62% conf

Yes	8%
No	92%

PortWatch transits are running ~5–13/day in early-mid September versus the ≥60 7-day MA threshold required, and the disruption has persisted ~7 months with two ceasefires collapsing within weeks and an active tanker attack as recently as Aug 27. Even after CENTCOM's Aug 28 mine-clearing claim, traffic did not rebound, and S&P Global notes crew/vessel safety (not insurance) is the binding constraint, implying a slow ramp even after any formal reopening. The only market anchor is Polymarket at 8.5% YES (down from 22.5%, -12pts/30d), with the Dec 31 deadline only at 18.5%. A Yes requires a sudden durable deal plus a ~5–10x traffic ramp within ~7 weeks — possible but no trigger is evident, so I stay near the market anchor at 8%.

gpt-5.6-sol

76% conf

Yes	8%
No	92%

The best available proxy anchor is Polymarket's 8.5% YES price, since no Kalshi-direct price was retrieved. Recent traffic of roughly 5–13 daily transits is far below the required 60-transit 7-day average, with no sustained upward trajectory despite reported mine-clearing. Two failed ceasefires, continued vessel attacks, extreme war-risk premiums, and persistent crew-safety concerns make a durable reopening within seven weeks unlikely. A rapid rebound remains mechanically possible after a genuine settlement, so YES retains an 8% probability.

5. Devil's Advocate Sonnet 5 · red-team critique

Both forecasts converge suspiciously precisely at 8.0% YES, essentially anchoring directly to the Polymarket proxy without independently stress-testing whether that market itself might be mispriced or stale (30-day volume only $608K, thin liquidity) — neither forecaster flags the risk of over-anchoring to a single, non-Kalshi, low-volume cross-market price.

Neither forecast grapples with the actual event-window math: even the brief's own "Yes" case notes recovery could hit 60/day within 1-3 weeks of a genuine reopening, and ~7 weeks remain — the forecasters state this scenario but don't decompose it into a probability of (durable deal occurring in next 7 weeks) × (ramp succeeding), instead just deferring to the aggregate anchor, which risks under- or over-shooting the true conditional structure.

The brief explicitly notes the code_execution model's alternative estimate (~25-50%, central 38%) but flags it as likely stale/overstated post-September collapse — neither forecaster explicitly explains why they discount this competing estimate to under 10% rather than, say, 15-20%, leaving a reasoning gap on how much weight the "pre-collapse" model deserves versus the newer Polymarket data.

Both treat the Aug 25 Iran-Oman mine-clearing/corridor agreement and Aug 28 CENTCOM confirmation as essentially non-events since traffic didn't rebound, but neither considers a lagged-effect scenario where cleared mines plus a corridor framework could produce a delayed ramp-up in late September/October that hasn't yet shown in the Sept 6-10 data cited (the brief itself flags "no PortWatch data point later than ~Sept 10" as a gap) — this is a plausible upside scenario neither forecaster explores.

Neither forecast addresses the asymmetry in the resolution mechanism itself: since resolution is "purely mechanical" hitting a 7-day MA threshold, a single geopolitical shock (e.g., regime change, major US-Iran deal) could cause a step-function jump that neither forecaster's narrative-driven ~8% accounts for as a fat tail — the probability may be too low if such discrete/binary trigger events (not modeled in the gradual "no current trigger" framing) have even modest likelihood over a 7-week window given how volatile this conflict has been (two ceasefires already signed and collapsed in under 5 months).

Both forecasters set confidence levels (0.62 and 0.76) without justifying the confidence metric itself — given the significant gaps flagged in the brief (no confirmed Kalshi price, no data past Sept 10, uncertain lag effects from mine-clearing), a lower or more clearly justified confidence would better reflect the actual evidentiary uncertainty rather than presenting near-identical point estimates with different unexplained confidence levels.

6. Aggregator Fable 5.1 · final calibrated forecast

9% (69% confidence)

Yes: 9% No: 91%

Transits remain at ~5–13/day in early-mid September against a mechanical ≥60 7-day MA threshold, with no rebound in the two weeks after CENTCOM's mine-clearing confirmation and an active tanker attack on Aug 27, so the base case is continued sub-60 traffic through Oct 31. Both forecasters agreed on this inference and anchored on the Polymarket 8.5% proxy; the critique's fat-tail point has some merit (two ceasefires were signed in five months, and a genuine settlement could produce a 1–3 week exponential ramp), but the related Polymarket ladder (Sept 30 at 1.7%, Dec 31 at 18.5%) and the blockade-end-by-Sept-30 market at 19.5% imply the market already prices a discrete-deal tail roughly consistent with 8–10% for Oct 31. The stale code_execution estimate (~38%) predates the September collapse and treats a reopening decision as likelier than current evidence supports, so it merits little weight. I nudge slightly above the anchor to 9% to account for thin liquidity and the data gap after Sept 10, but the decomposition (P(durable deal in ~7 weeks) × P(shipowners ramp to 60 fast enough given crew-safety constraints)) does not justify materially more.

Pipeline Timing

Total pipeline time: 318.6s

Per-tool research timings shown in the Research section above.