Key TakeawaysShares of steel and aluminum manufacturers jumped Monday after President Donald Trump said he planned to implement new tariffs on imports of the two metals.Trump also said he would be slapping retaliatory tariffs on countries that put tariffs on U.S. goods.Canada is the biggest exporter of steel and aluminum to the U.S., and the country's Minister of Innovation, Science, and Industry argued Canadian goods support many U.S. industries. Shares of steel and aluminum producers, including Cleveland- ...