The Strait of Hormuz handled an average of 3.6 vessels a day in September, 95% below the 68.1 a day it averaged between January 1 and February 27, according to IMF PortWatch daily counts. Brent closed at 100.58 on October 6. For Canada, the closure works as a transfer: Statistics Canada reported on October 6 that August energy exports rose 4.7%, the first increase since April, and that the merchandise trade surplus widened to $4.2 billion from $787 million in July.
How a Closed Strait Becomes a Canadian Trade Surplus
The chain runs through price. Exports of refined petroleum products rose 17.4% in August, and Statistics Canada said export prices for those products were up more than 50% from a year earlier. Crude oil exports rose 2.1% on higher prices. It was the sixth consecutive monthly surplus, and the Canadian dollar averaged 1.1 US cents higher in August than in July, the strongest monthly gain since December 2025.
The same shock reaches Canadian households through the pump. Gasoline was up 22.8% from a year earlier in the August consumer price index, which is why the closure is also a Bank of Canada story ahead of its October 28 decision. Canadian energy exposure holds the long side of the Hormuz trade, and fuel-buying households hold the short side.
Weekly average transits fell from 77.6 a day in the week of February 23 to 2.6 in the week after the war began, recovered only to 30.4 in the week of June 22, and stood at 2.7 in the latest full week.
Each point is the seven-day average of daily vessel counts for a week beginning Monday, and the latest week runs September 28 to October 4. The shaded weeks are those in which daily counts exceeded 20 on 15 days between June 18 and July 8.
June Showed How Fast the Premium Can Reverse
Between June 18 and July 8, daily transits exceeded 20 on 15 days, and the effect on Canadian energy revenue was immediate. June energy exports fell 10% to $18.37 billion, which Statistics Canada attributed to a momentary respite in the Middle East war lowering energy prices. CBS News reported that Brent had climbed from about $72 in early July to $97.54 on September 8, briefly touching $99.46. A return from the current 100.58 to $72 would be a fall of about 28%.
That is the tail risk, and it is a reversal, not an escalation. The base case on the evidence is persistence. Iranian parliament speaker Mohammad Bagher Ghalibaf has said the strait stays closed until seven Iranian conditions are met, and Iran is still reviewing the US response to its seven-point plan. The June safe-passage memorandum collapsed, and a repeat would need to survive what the first version did not.
The Risk Is Also Escalating at Sea
The UK Maritime Trade Operations centre reported on September 30 that three ships, including a crude tanker and an LNG tanker, were struck by unidentified projectiles on September 29. A tanker was hailed by Iranian Revolutionary Guard forces and turned back about 11 nautical miles north of Khasab, Oman, at 08:27 UTC on October 5, under advisory 152-26. On October 4 the product tanker Lipsi was struck, and 12 seafarers were injured when a projectile hit an LR2 tanker, according to the maritime tracker straits.live. The tracker counted 203 vessels holding position on October 6.
Goldman Sachs raised its near-term oil forecasts on September 8 and said Brent could pass $120 in 2027 if escalation continues. The range of outcomes for a Canadian energy position therefore runs from a 28% reversal on a reopening to a move above $120 on a prolonged war, and the trade surplus, the exchange rate and the October 28 rate decision all move with it.