Markets had dismissed tariff risks under the assumption that Trump would follow an earlier pattern and back off, in what became known as the so-called TACO trade. That allowed stocks to reach new record-high territory recently, marking a stunning rebound from the collapse triggered by his “Liberation Day” reciprocal tariffs in April.

Late Thursday, Trump posted a letter threatening to impose 35% tariffs on goods from Canada. The barrage of letters began on Monday, setting tariffs of 25% on goods from Japan and South Korea and 50% on Brazil.