Shares of steel and aluminum companies outperformed broader stock benchmarks Tuesday after President Trump said in a social media post that he would boost the planned 25% tariff on Canadian imports of the metals to 50% in the escalating trade war between the countries.

Global markets have been gripped by a sense of risk aversion ever since U.S. President Donald Trump triggered a tit-for-tat tariff war between the U.S. and its trade partners, which analysts have said could stoke inflationary pressures and trigger an economic slowdown.