The Canadian dollar was sliding following President Trump's threat of a 35% tariff against Canada. But the bigger picture is what it might presage for U.S. negotiations with the European Union. The U.

Major stock indexes were slightly lower on Friday as U.S. President Donald Trump's announcement of tariffs on imports from Canada fanned worries about trade tensions, with the Canadian dollar down against the greenback.

President Donald Trump late Thursday threatened a 35% tariff on goods imported from Canada, a dramatic escalation in an on-again, off-again trade war with America’s northern neighbor and one of its most important trading partners.