U.S. stock markets reacted negatively on Monday after President Trump announced via social media that he would unilaterally impose 25% trade tariffs on Japan and South Korea. The tariffs target two of America’s closest allies and key suppliers of autos,

It’s a possible sign that President Donald Trump’s wave of tariff letters is again raising concern among investors.

Trump's moves have raised fears that economic growth would slow to a trickle, if not make the U.S. and other nations more vulnerable to a recession.