Investors were concerned about worsening U.S.-Iran relations after news that the U.S. military had killed Qassem Soleimani, the head of Iran's Islamic Revolutionary Guard's Quds Force. The strike also killed Abu Mahdi al-Mohandes, the deputy head of the Popular Mobilization Forces, which is an umbrella for dozens of militias that are part of the Iraqi security apparatus but include factions that swear allegiance to Iran's supreme leader.
