WTI closed at $89.38 on September 29, 12.8% below its September 10 close, as Saudi pipeline repairs and reserve releases outweighed a rejected ceasefire proposal and a growing US naval presence.

Estimates of oil moving through the strait range from 3.7 to 16.4 million barrels a day. Iran offered a seven-day reopening, Washington rejected the sequencing, and Brent moved less than 3% on either headline.

Qatar is carrying an amended proposal, President Trump expects a deal only after the November midterms, and Brent settled at $102.59 after a 13% September gain.

WTI closed lower on the day Washington turned down Tehran, because Middle East exports are at a wartime high and talks resume this week, which keeps Canadian energy names supported but not unconditionally.

A 50 percent US tariff on Canadian goods took effect the same month Brent crude spiked above $108 on Strait of Hormuz attacks, and the two shocks are pulling the same index in opposite directions.

Commercial transit through the Strait fell to about one percent of normal this week, yet WTI crude sits more than ten dollars below its September peak. The gap between the disruption and the price is the story.

Iran has offered to reopen the Strait of Hormuz within seven days if U.S. military pressure eases, and Brent crude jumped 4.4% to $103.61 on the news rather than falling, because the mechanism connecting that offer to Canadian energy portfolios runs through whether the ceasefire actually holds, not through the headline alone.

WTI crude has fallen for six straight sessions, from a peak of $105.83 on September 15 to $90.56 Wednesday, on hopes of US-Iran diplomacy and a Saudi pipeline workaround, well ahead of any confirmed change to Strait of Hormuz shipping.

WTI crude gained nearly 20 percent as the Strait of Hormuz crisis intensified. The TSX energy sector gained barely 2 percent on the same day.