Trump wants to come after Brazil steelmakers. What to expect?

Monday got off to a turbulent start after U.S. President Donald Trump used his Twitter account to threaten Brazil and Argentina with new import tariffs on steel products. Mr. Trump accused both countries of “presiding over a massive devaluation of their currencies” to make their agricultural products more competitive in the U.S. market, promising a retaliation in line with the stance he has taken towards China.

Mr. Trump’s tweets have had a sharp effect on markets—to the point that JPMorgan created the “Volfefe Index,” a portmanteau of the words volatility and Mr. Trump’s infamous “covfefe” tweet in 2017. Many expected Brazilian steel companies to crash today, following Mr. Trump’s morning tweet. 

However, that was not the case. Instead, stocks of the country’s main players went up.

And that’s because of the limited effects Mr. Trump’s promised tariffs would actually have on them.

Back in March 2018, the U.S. president announced a bump in tariffs on steel and...