**Geopolitical risks from renewed Houthi activity have driven Bab el-Mandeb transits sharply lower since mid-July, producing closely matched Polymarket probabilities across the four buckets.** After the Houthis declared a Saudi maritime blockade in late July amid the broader 2026 Iran-related tensions, weekly vessel counts fell roughly 24% from 354 to the 266–269 range, then stabilized near 226 crossings for 3–9 August per Lloyd’s List Intelligence and MarineTraffic data. This reflects shipowners rerouting around the Cape of Good Hope, elevated war-risk insurance premiums, and selective avoidance of Saudi-linked cargoes, partially offset by a multinational naval coalition and Houthi denials of new transit fees. **The narrow spread between the 180–199 (34.5%) and 220+ (33.0%) outcomes captures residual uncertainty over modest week-to-week volatility.** Daily crossings have fluctuated between the low 20s and low 40s, with some rebound to 40 on 11 August amid hopes of de-escalation in the U.S.–Iran conflict. Key swing factors include the pace of any security incidents, the share of tankers and container ships electing to transit versus divert, and the effectiveness of “safe passage” assurances. Markets are pricing in continued depressed but not collapsed volumes relative to pre-July levels, consistent with the strait’s role as a critical chokepoint for roughly 10% of seaborne oil and a significant share of Europe–Asia trade.