Which countries will send warships through the Strait of Hormuz by August 31?

Platform comparison

Market context

The key question is whether any national navy publicly sends a warship through the Strait of Hormuz before the deadline, not whether commercial shipping resumes. That distinction matters because the market settles only on military or military-support vessel transits, so headlines about tankers, escort offers, or general “safe passage” arrangements do not by themselves create a Yes outcome. In platform terms, Polymarket-style markets usually frame this as an implied probability, while Kalshi and Smarkets present prices differently, and Betfair adds exchange-style depth plus commission, so the same event can look cheaper or more expensive depending on fees, liquidity, and KYC access.

Historically, the 8% crowd price reads as a low-probability diplomatic-and-operational bet rather than a pure conflict bet. In March, Trump publicly urged the UK and other nations to send warships, but Reuters and other outlets reported that allies largely rebuffed the call and no broad multinational deployment followed[1][6][16]. During the 2026 Hormuz crisis, there were repeated reports of shipping disruption and some countries seeking clearance for merchant vessels, yet those are not the same as warship transits, which keeps the resolution bar high[7][11][13][15]. That makes the market more sensitive to official naval statements than to oil-market volatility.

The main catalysts are therefore defence ministry announcements, coalition escort plans, port-call schedules, and any verified transit report from a credible wire service or government source. Reuters reported in late June that traffic had rebounded and the UN later said shipping was near standstill again in July, showing how quickly the operational picture can shift[14][13]; any new escalation around Iranian attacks or US reassurance efforts could prompt allied navies to respond[15]. On platform comparison, Betfair and Smarkets can react faster if there is live trading momentum, but Kalshi and Polymarket may be more useful for clean probability reads; whichever venue a trader uses, KYC coverage and local access will matter more than usual because some books exclude US users or apply stricter verification.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Which countries will send warships through the Strait of Hormuz by August 31? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.