Oil prices surged past $100 a barrel after weekend peace talks between the U.S. and Iran collapsed without resolution. Brent crude gained 6.8% to $101.70 while West Texas Intermediate rose 7.2% to $103.55. The breakdown in negotiations came as President Trump announced a U.S. blockade on vessels entering or leaving Iranian ports would take effect at 10 a.m. Eastern Time.

Market optimism that had lifted stocks late last week evaporated as investors reassessed the fragile cease-fire. U.S. Treasurys fell while Japan's benchmark government bond yield jumped to a near 30-year high. Natural gas prices also jumped, with the European benchmark Dutch TTF contract up 9% to 47.58 euros a megawatt-hour. Meanwhile, Hungarian assets rallied following Peter Magyar's election win amid broader European losses.

Traders are now looking to major bank earnings for insight into how Middle East conflict is affecting corporate performance. Goldman Sachs reports Monday before J.P. Morgan, Citigroup and others report Tuesday. Helima Croft of RBC Capital Markets warned that deadlocked negotiations over Washington's zero uranium enrichment demand set the stage for further escalation and prolonged supply disruptions ahead of summer driving season.