Politics Middle East

Bab el-Mandeb Strait effectively closed by…?

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December 31
$562.67K Vol.
21% 5.5%
October 31
$161.37K Vol.
13.5% 5%
September 30
$2.55M Vol.
9.2% 4.8%
September 15
$297.8K Vol.
1.1%

Odds summary

December 31 currently leads the Bab el-Mandeb Strait effectively closed prediction market at 21% 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.

Volume$12.46M Liquidity$236.96K Open Interest$1.13M Last updated7 mins ago

Odds, liquidity, volume, and open interest are sourced from Polymarket and last synced at Sep 10, 2026 8:57 am.

CryptoSlate Market Analysis

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.

Aerial view of cargo ships and oil tankers halted by patrol vessels across the narrow Bab el-Mandeb Strait under storm clouds.

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 31 price implies a minority chance that ship arrivals fall to the rule’s closure threshold at least once before year-end.

Higher prices at later deadlines frame the risk as cumulative over time rather than as an expectation of an immediate, sustained shutdown.

Mixed signal 67% CatalystA qualifying PortWatch reading before December 31 RiskThreshold is narrower than broad closure

What could reprice it

Future PortWatch readings through December 31 are decisive: any seven-day average of 10 or fewer arrivals determines a Yes outcome for that deadline.

Because a single qualifying observation is sufficient, each published rolling average can materially alter pricing before the relevant listed date.

Strong signal 83% CatalystPortWatch publishes a seven-day average at or below 10 RiskNo qualifying reading occurs

Where the market may be weak

The contract measures a narrow arrivals threshold, so it can diverge from the broader idea of an ‘effective’ Bab el-Mandeb closure.

Resolution does not require evidence of a complete navigation halt; it requires only one published seven-day average of 10 or fewer arrivals.

Rules risk 72% RiskProxy-to-headline mismatch

Counter-signal

The 0.7% September 15 price is the clearest counter-signal: participants assign very little chance of a qualifying disruption within days.

The gap to 17% by December 31 indicates time accumulation drives the thesis, leaving it exposed if early PortWatch readings remain above 10.

Mixed signal 62% CatalystEarly PortWatch readings stay above 10 RiskLater deterioration can still qualify

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”.
Platform
Category
Politics Middle East
Close date
January 1, 2027, 4:59 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 21%, October 31 at 13.5%, September 30 at 9.2%, and September 15 at 1.1%. These probabilities are market-implied and can change as liquidity and trading activity update. The latest market snapshot includes $12.46M volume, $236.96K liquidity, and $1.13M open interest. CryptoSlate last synced this market data at Sep 10, 2026, 07:57 UTC.

What could move the Bab el-Mandeb Strait effectively closed by… prediction market odds?

The December 31 price implies a minority chance that ship arrivals fall to the rule’s closure threshold at least once before year-end. Higher prices at later deadlines frame the risk as cumulative over time rather than as an expectation of an immediate, sustained shutdown. Catalysts to watch include A qualifying PortWatch reading before December 31, PortWatch publishes a seven-day average at or below 10, and Early PortWatch readings stay above 10.

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.

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