U.S. equity futures tumbled in early Monday trading, while energy prices leaped and the dollar soared to a two-year high against its currency peers as markets reacted to the weekend tariff announcements of President Donald Trump and their potential to trigger a global trade war.

Investors bought dollars, sold stocks and fretted about inflation on Monday in a scramble to assess the risk of trade war after Donald Trump put tariffs on top U.S. trading partners. Trump's orders for additional levies of 25% on imports from Mexico and most goods from Canada,

Having lived with the risk of a US-led trade war for weeks, financial markets reopen Monday needing to deal with the reality.