John Authers, Columnist

Tariffs Show the Market Guardrail May Be Overrated

And it’s getting harder to ignore the economic warning signs.

March 4, 2025 at 5:00 AM UTC

John Authers is a senior editor for markets and Bloomberg Opinion columnist. A former chief markets commentator at the Financial Times, he is author of “The Fearful Rise of Markets.”

Border crossing at St-Bernard-de-Lacolle, Quebec. — Border crossing at St-Bernard-de-Lacolle, Quebec.
Photographer: Andrej Ivanov/Bloomberg

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The US president announced at 2:42 p.m. Eastern Time that tariffs on Canada and Mexico would commence Tuesday. Many had complained that the market had grown too complacent about tariffs. Judging by the instant reaction, they were right. The vertical lines in the chart indicate the timing of the announcement: