The Iranian campaign against tankers leaving the Strait of Hormuz cut weekly tanker volumes through the strait by 15% in the week of October 5 to 11, according to Windward maritime data, and the effect reaches Canadian portfolios through three channels: the price of oil, Canadian inflation and the Bank of Canada decision on October 28.
The escalation is documented. The United Kingdom Maritime Trade Operations reported on October 12 that an oil tanker was struck by an unidentified projectile as it exited the strait, and Windward counted six vessels hit around Hormuz on October 11. Reuters reported at least 12 attacks on oil, liquefied natural gas and liquefied petroleum gas tankers between September 28 and October 5. Eighty-seven percent of the 45 ships Iran targeted in the third quarter were tankers, according to Al Jazeera, and Mohsen Rezaei of the Supreme National Security Council said on October 11 that forces were targeting five or six vessels each night.
Channel One: Brent at $105.69 and WTI Near $94
Brent closed at $105.69 on October 13, up 49.5% from $70.69 at the end of January. The November WTI contract traded near US$94 per barrel on Tuesday, against an October 2025 average of $60.26. Canadian producers price off WTI and Western Canadian Select, so the 56% rise in WTI over twelve months is the figure that matters for Toronto-listed energy earnings. The S&P/TSX composite gained 0.9% on Tuesday with energy leading.
Brent held between $95.41 and $108.75 across 22 sessions, with three moves of 7% to 9% inside a single week, which shows a market repricing tanker risk daily and not settling on a level.
Brent fell 7.35% on September 21, rose 8.64% on September 24 and fell 7.30% on September 25; the October 11 attacks preceded a 1.84% rise on October 12. Source: Investing.com.
Channel Two: Energy Inflation and the Bank of Canada
Continuum Economics expects the September consumer price index, due October 19, to show headline inflation at 3.0% for a third straight month, driven by energy, with the three Bank of Canada core measures near or below 2.5%. That is the transmission from Hormuz to monetary policy: oil raises headline prices while the labour market weakens, and the overnight rate sits at 2.25% with a decision due October 28.
Canada lost 68,300 jobs in September, yet Alberta, the oil-producing province, added 23,000. The Canadian dollar traded at 70.31 US cents on Tuesday after falling to 69.99 following the jobs report, so oil strength is not translating into currency strength.
Base Case, Upside and the Saudi Bypass Tail Risk
The base case is persistent harassment without a full closure. Fourteen vessels still transited Hormuz on October 12, eight inbound and six outbound, though six of the 14 ran dark with transponders off, according to Windward. A southern corridor near Oman and a US-UAE shuttle system move crude beyond the strait, which is why flows fell 15% and did not collapse.
The upside scenario is a negotiated reopening. Iran has claimed the United States accepted some of the seven conditions Tehran has set for fully reopening the strait, but no agreement has been confirmed.
The tail risk is the bypass. Rezaei accused Saudi Arabia of helping the United States move oil around Iranian restrictions, and Windward noted that any move against Saudi-linked tankers in the Red Sea would hit the main bypass route. Bab-el-Mandeb crossings on October 12 were 22 into the Red Sea and 12 out, against seven-day averages of 17.6 and 19.3. A disruption there would remove the release valve that has kept the price of Hormuz disorder below its worst case.
HDQ treats persistence as the base case, a deal as a lower-probability upside and a Red Sea disruption as the tail risk to monitor. The September CPI on October 19 and the Bank of Canada decision on October 28 are the next two points where oil shows up in Canadian data.