Stock futures dropped Thursday night after Trump announced the 35% tariff on Canada, set to take effect on August 1. The S&P 500 was on track to snap back-to-back days of gains.

US stock market slipped in early trading on July 11, pulling back from record highs as Trump’s tariff threat on Canada spooked investors. The S&P 500 fell 0.4% after hitting a record the previous day, ...