Bab el-Mandeb Strait effectively closed by…?
Odds summary
December 31 currently leads the Bab el-Mandeb Strait effectively closed prediction market at 22.5% reported probability on Polymarket. The figures below combine live odds, liquidity, volume, and open interest so readers can compare the market signal before reading the full analysis.
Odds, liquidity, volume, and open interest are sourced from Polymarket and last synced at Aug 20, 2026 8:47 pm.
Bab el-Mandeb Curve Favors Acute Shock Over Gradual Closure
The rising deadlines encode a front-loaded hazard: an acute disruption has the clearest near-term path to the IMF’s traffic threshold, while later contracts accumulate additional routes to settlement. The decisive issue is sustained measured ship scarcity, regardless of whether authorities formally declare the strait closed.

The price hierarchy implies that a closure-scale event is most plausible as a sudden operational shock, with progressively smaller additions from prolonged attrition. July 31 is priced at 10%, August 31 at 19%, September 30 at 23.5%, and December 31 at 33.5%. Because each contract covers the period from market creation through its deadline, the meaningful signal lies in the gaps between dates. Those gaps favor an early shock over a steadily intensifying path through year-end.
The curve concentrates hazard in July and August
The nine-point increase from July to August implies roughly a 10% conditional probability of first crossing the threshold during August, given no qualifying reading by July 31. September adds 4.5 points, equivalent to about 5.6% conditional on no earlier settlement. December adds another 10 points across three months, or approximately 13.1% conditional on surviving September.
These are market inferences from quoted prices, rather than independent forecasts. They suggest that the first two monthly windows carry a higher hazard rate than the autumn extension. The December contract’s 33.5% price therefore should not be read as a forecast concentrated in December; most of its probability is inherited from earlier deadlines.
PortWatch’s threshold separates closure language from settlement
The rules define effective closure through one observable: IMF PortWatch must publish a seven-day moving average of Bab el-Mandeb transit calls, labeled “Arrivals of Ships,” at or below 10. A government declaration, naval warning, attack, obstruction, or carrier announcement has settlement relevance only through its effect on that published average.
This creates two hidden assumptions. First, disruption must be deep or persistent enough to pull a rolling average through 10. An isolated low-traffic day may have little effect if surrounding days remain active. Second, a qualifying reading could arise without a formal closure. Hypothetical causes include widespread voluntary rerouting, physical blockage, sustained attacks, military restrictions, or operating decisions that sharply reduce transits.
The missing traffic baseline limits geopolitical conclusions
The supplied record provides the threshold and settlement source, but no current PortWatch reading or recent trend. That missing baseline determines how much disruption is required. A moving average already near 10 would make modest additional rerouting consequential. A reading far above 10 would require a larger and longer shock.
Evidence favoring the market’s near-term hierarchy would include several consecutive weak daily observations that pull the seven-day series toward the threshold. Stable readings comfortably above 10 would weaken the acute-shock thesis, even amid elevated regional rhetoric. The metric’s trajectory carries more direct resolution value than broad descriptions of maritime tension.
Concrete catalysts must alter a full seven-day path
The clearest repricing catalysts would be events capable of changing multiple consecutive traffic observations:
- A physical obstruction, sustained attack campaign, or enforceable maritime restriction that interrupts passage.
- Documented carrier rerouting broad enough to reduce total transit calls for several days.
- PortWatch readings approaching 10, especially when the weakest observations begin filling most of the rolling window.
- Restored transits, security arrangements, or carrier resumptions that replace low observations before the average crosses the threshold.
A PortWatch publication at or below 10 would settle every contract whose deadline includes that date. A dramatic event followed by rapid traffic recovery could still fail to qualify because the seven-day averaging rule filters brief disruptions.
Cumulative exposure is the main counter-signal
The strongest alternative explanation is simple elapsed time. Later contracts contain every earlier route to settlement plus additional days, so rising prices do not by themselves establish expectations of worsening conditions. The 10-point increase from September through December spans roughly three times the calendar exposure of either preceding monthly step, reinforcing the interpretation that marginal hazard declines after summer.
Aggregate activity gives the curve some informational weight: the event reports $6.31 million in volume, $248,110 in liquidity, and $667,220 in open interest. Those totals cannot establish that each deadline is equally liquid or that buyers possess superior information. The June 30, 2026 market close also should not be confused with the qualifying windows, which end on each contract’s listed date. Fresh PortWatch data remain the evidence most capable of separating a geopolitical narrative from a settlement-relevant traffic collapse.
Sources
What could move the odds?
Informational summary of factors that may affect the reported prediction-market probabilities.
Market-implied thesis
The December price implies a minority chance that Bab el-Mandeb arrivals hit the rule’s severe 10-or-fewer seven-day average by year-end.
The claim is about a qualifying PortWatch reading on any date through December 31, not a general assessment of shipping disruption or regional risk.
What could reprice it
A PortWatch publication showing the seven-day arrivals average at or below 10 before the August 31 deadline would most sharply reprice the nearest contract.
Because resolution depends on any qualifying daily observation, an official threshold breach—not commentary on maritime conditions—would directly establish the August outcome.
Where the market may be weak
The page’s June 30 close date is already past despite an open status and later-dated outcomes, creating a material freshness and market-state ambiguity.
Its $10.82M cumulative volume does not prove current price-setting depth; the displayed $474.94K liquidity and absent trader count give limited evidence on participation.
Counter-signal
The sharp gap between August’s 1.6% and December’s 22.5% implies the market itself sees an immediate threshold breach as much less likely than a later one.
That term structure challenges any reading that closure is already imminent: the required seven-day average may remain above 10 even if disruption persists or attracts attention.
Market details
- Resolution criteria
- This market will resolve to “Yes” if IMF PortWatch publishes a 7-day moving average of transit calls (“Arrivals of Ships”) for the Bab el-Mandeb Strait less than or equal to 10 for any date between market creation and the listed date. Otherwise, this market will resolve to “No”.
- Category
- Politics › Middle East
- Close date
- June 30, 2026, 12:00 AM UTC
- Settlement source
- portwatch.imf.org
- Market rules summary
- Multi-timeframe Polymarket event. Each listed timeframe is represented by its Yes price on the underlying binary market. View full rules
Frequently asked questions
What are the current Bab el-Mandeb Strait effectively closed by… odds?
Polymarket reports Bab el-Mandeb Strait effectively closed by… odds with December 31 at 22.5%, September 30 at 10.5%, and August 31 at 1.6%. These probabilities are market-implied and can change as liquidity and trading activity update. The latest market snapshot includes $10.82M volume, $468.57K liquidity, and $1.19M open interest. CryptoSlate last synced this market data at Aug 20, 2026, 19:47 UTC.
What could move the Bab el-Mandeb Strait effectively closed by… prediction market odds?
The December price implies a minority chance that Bab el-Mandeb arrivals hit the rule’s severe 10-or-fewer seven-day average by year-end. The claim is about a qualifying PortWatch reading on any date through December 31, not a general assessment of shipping disruption or regional risk. Catalysts to watch include PortWatch qualifying reading before Dec. 31, PortWatch daily seven-day arrivals data, and Verification of live contract status.
How does the Bab el-Mandeb Strait effectively closed by… prediction market resolve?
This market will resolve to “Yes” if IMF PortWatch publishes a 7-day moving average of transit calls (“Arrivals of Ships”) for the Bab el-Mandeb Strait less than or equal to 10 for any date between market creation and the listed date. Otherwise, this market will resolve to “No”. Multi-timeframe Polymarket event. Each listed timeframe is represented by its Yes price on the underlying binary market. The settlement source listed for this market is Portwatch.