‘Tehran’s tollbooth’: a visual guide to how a trickle of ships still passes through strait of Hormuz

The Strait of Hormuz has been effectively closed for four weeks, disrupting roughly 20% of global oil and gas flows and about one-third of global fertiliser shipments; normal transit (~138 ships/day) collapsed to about a month's worth in March. An estimated 1,000 vessels have anchored or remained in port and ~20,000 seafarers are stranded, with >20 attacks reported and at least one transit payment reportedly as high as $2m (paid in yuan). Iran is routing traffic through an Iranian 'safe corridor' enabling IRGC visual verification and control, raising risks of delays, seizures or informal tolls. Expect persistent supply tightness, higher energy prices and elevated shipping insurance premia with volatility lasting months even after active hostilities end.

Analysis

The shock to seaborne flows has immediate, quantifiable cost inflation in logistics: longer voyage distances and mandatory sequencing raise bunker consumption and idle time, which can increase a single VLCC voyage cost by low‑seven figures and push spot charter rates sharply higher for as long as uncertainty persists. That dynamic compresses delivered supply to importing regions, creating localized contango in refined products and short, sharp inventory draws in destination hubs that can persist for weeks-to-months while alternative routing and sequencing scale up.

Second‑order winners will be asset owners who can flex capacity (older tankers, mid‑size bulkers) and ports that become transshipment or re‑bunkering hubs, capturing both time-charter premium and ancillary fees; conversely, firms with tight just‑in‑time procurement (fertiliser blenders, some petrochemical feedstock users) face margin squeeze and substitution risk, raising defaults or demand destruction in the next 1–3 quarters. Financially, faster recognition of war‑risk premiums should boost underwriting income for specialty marine insurers and brokers over the next 1–4 quarters, while increasing compliance and settlement frictions for banks handling atypical currencies and escrow arrangements.

The path back is binary and headline‑driven: a coordinated security corridor or effective naval escort that measurably reduces incident rates to near‑zero for 30+ days would deflate premiums and freight spikes within weeks; sustained asymmetric attacks or factional seizures would institutionalize higher costs and rerouting for months to years. Monitor real‑time indicators (spot tanker rates, bunker spreads, AIS port queuing metrics) as high‑frequency signals to scale exposure up or down.

Key Decisions for Investors

• Long selective tanker owners: DHT Holdings (DHT) and Frontline (FRO) — initiate 3–6 month in‑the‑money call spreads (~25–35% notional) to capture uplifts in VLCC/time‑charter rates; upside if rates remain elevated, downside limited to premium paid if rapid de‑escalation occurs. Target 2–3x option IRR if elevated rates persist for 2+ months; cut 50% on 30% rally or if incident rate drops to pre‑crisis norms for 14 consecutive days.
• Long container/shipping exposure via ZIM Integrated Shipping (ZIM) — buy 3‑month stock or calls (size 1–2% portfolio) to play sustained freight rate power; high convexity to tight capacity but vulnerable to demand destruction — take 40% profits if global transits/volumes slip month‑over‑month by >5%.
• Long marine insurance/underwriting exposure: Chubb (CB) or Allianz (ALIZY) — buy 6–12 month calls or a modest equity overweight (1–2%) to capture front‑loaded premium recognition; downside is large war‑loss aggregation, so size defensively and hedge with a 6–12 month long‑dated put position at a strike ~15% below cost.
• Long selected fertiliser producers (CF Industries CF or MOS Mosaic MOS) — purchase 3–9 month call verticals (conservative notional) to capture price pass‑through from constrained seaborne supply; risk is demand destruction or tariff relief–driven imports — set stop if freight basis normalizes or crop‑planting demand revisions fall >10%.