Stock futures were falling markedly in premarket trading Tuesday after shares staged a rally in the previous session. There wasn’t one clear reason for the turnaround, but rather a combination of at least three things.

President Donald Trump started his second term two months ago, but his trade policy has already shaken the stock market. His administration has either imposed or plans to impose tariffs on imported goods from several countries,

The Dow was 540 points lower, or 1.3%, in morning trading. The broader S&P 500 fell 1.1% and the Nasdaq Composite fell 0.8%.