Oil prices spiked above $100 per barrel on Sunday evening after U.S.-Iran peace talks collapsed overnight. President Trump then announced plans to blockade the Strait of Hormuz, a critical shipping route that typically carries roughly one-fifth of the world's oil supply. The dual developments sent markets tumbling before Monday's trading session.

Brent crude, the global benchmark, jumped more than 7% to approximately $102 a barrel. West Texas Intermediate rose over 8% to about $105 a barrel. S&P 500 futures slipped roughly 1%, erasing some of the 3.6% weekly gain the index had posted through Friday. The price surge marks a sharp escalation after a fragile cease-fire briefly stabilized markets last week.

Trump's blockade strategy mirrors recent pressure on Venezuela. U.S. Central Command clarified forces would only intercept vessels traveling to and from Iranian ports. Consumers are already feeling the pain: gasoline averages $4.13 a gallon, up 38% since the war began, while diesel has climbed to $5.66, a 50% increase. Few vessels are attempting the Hormuz passage due to attack fears.