The S&P/TSX Composite Index closed at 35,933.27 on Wednesday, down 402.34 points, or 1.1%, one session after gaining 326.21 points on Tuesday. The same sector drove both moves in opposite directions: base metal shares, which led the Tuesday advance on gains in materials and technology names, gave the move back Wednesday as copper retreated from near record levels.
Energy names cushioned the decline rather than adding to it. WTI crude added 80 cents to $91.32 per barrel on the November contract, holding near the elevated range it has occupied since the Iran conflict pushed prices sharply higher earlier this year, and that stability kept the index loss from being worse.
Why the CAD Moved Against the Copper Story Today
The Canadian dollar weakened to 70.93 cents U.S. from 71.10 cents, and gold fell $59.30 to $4,317.10 an ounce in the same session. Both moves share a mechanism: the U.S. Federal Reserve raised its target range to 3.75 to 4.00% on September 16, its first hike since 2023, and the resulting dollar strength is pressuring the commodities and currencies priced against it, copper included. Copper had been trading near record highs into this week on tight supply and AI-driven demand expectations, which made it the most exposed part of the TSX to a reversal once the U.S. dollar firmed.
The composite index has moved by more than 300 points in four of the past six sessions, and the chart below traces that swing against a five day moving average that has stayed comparatively flat, showing a market oscillating around a level rather than trending decisively in either direction.
The index has swung by more than 300 points in four of the past six sessions, with the five day moving average staying comparatively flat through the same stretch. Source: Investing.com; CP24.
What Wednesday Changes for Canadian Portfolios
A single volatile week does not, on its own, signal a change in trend. What it does confirm is that the same two mechanisms, energy prices anchored by the Iran conflict and a U.S. dollar responding to the Federal Reserve reversal, are now the dominant forces moving the TSX day to day, more than any single Canadian company story. Base metals and materials names carry the most exposure to further U.S. dollar strength, while energy names remain the sector most directly tied to how the Strait of Hormuz situation resolves over the coming days.