Oil prices climbed and U.S. stock-index futures, contracts that show where investors expect major indexes to open before trading begins, slipped on Sunday after the United States and Iran continued trading strikes near the Strait of Hormuz over the weekend. The exchanges marked another round in a back-and-forth pattern of attacks between the two countries. Markets were already moving before American trading began.
Why the Strait of Hormuz pulls oil prices
The Strait of Hormuz is a narrow passage of water at the mouth of the Persian Gulf, between the Arabian Peninsula and Iran. It serves as a major corridor for oil tankers leaving the Gulf for markets around the world. Military action near it puts traders on alert fast. The concern is simple: if ships cannot move freely, less crude reaches buyers, and tighter supply pushes prices higher.
That concern animated the weekend's moves. The United States and Iran continued what accounts described as tit-for-tat exchanges around the strait. Oil prices rose. The market does not wait for shipping lanes to actually close. The threat of disruption is enough to move prices on a Sunday.
How futures markets translate the news
When oil prices spike on geopolitical risk, stock-index futures tend to fall. Higher energy costs raise expenses for businesses throughout the economy. Investors anticipating those costs expect corporate profits to come under pressure, so they pull back from equities before markets open.
Sunday's futures decline followed that logic. The moves came in response to continued U.S.-Iran exchanges around the Strait of Hormuz over the weekend.
The market knows this trade well. Hormuz tensions rise, oil follows, futures fall.