The selloff offered an early glimpse of how Wall Street will respond to trade wars.

U.S. stock-index futures opened sharply lower and oil prices jumped Sunday night and investors braced for volatility across financial markets after President Donald Trump over the weekend announced heavy tariffs on imports from Canada,

Oil prices fell on Wednesday, with the U.S. benchmark settling at its lowest year to date, after domestic crude stockpiles in the world's top petroleum producer and consumer rose more than expected last week.

ConocoPhillips can generate that much cash at an oil price below $80 because of its low cost of supply. It has about 20 billion barrels of resources with a cost of supply of $40 per barrel or lower, with an average cost of supply of $32 per barrel. With crude prices in the $70s, ConocoPhillips can produce a lot of cash.

Oil prices rose on Monday after U.S. President Donald Trump imposed tariffs on Canada, Mexico and China, raising fears of supply disruption, though gains were capped by concern over what could be an economically damaging trade war.

Oil prices jumped in early trade after U.S. President Trump imposed hefty tariffs on major trading partners, raising fears of supply disruptions. Effective Tuesday, the U.S. will impose a 25% levy on imports from Canada and Mexico,