President Donald Trump has taken executive action to impose new tariffs on imports from Canada, China and Mexico.

Trump has long proposed raising tariffs—or taxes on imported goods that the businesses importing them pay the U.S. government—before the election, and said in November he’ll impose a 25% tariff rate on all imports from Mexico and Canada on the first day of his presidency and will impose an additional 10% tariff rate on all imports from China on top of other tariffs.

Just about everyone thought it was a bluff. Top analysts from the biggest banks on Wall Street said it was highly unlikely. Stocks were trading like it wouldn’t happen. Some companies built contingency plans but they weren’t exactly rushing to make changes.