LONDON, July 8 — On the last day of March 2025, the global oil market delivered a jolt that traders and analysts are still parsing months later. Brent crude futures surged by 5.8% to $78.50 per barrel, while West Texas Intermediate rose 5.9% to $74.20 per barrel. It was the largest single-day percentage increase since October 7, 2023, when prices jumped 6.2% following the Hamas attack on Israel.
For anyone tracking the energy landscape, the numbers tell a story of deep-seated vulnerability. Iran produced approximately 3.2 million barrels per day in 2024, exporting about 1.5 million barrels per day, with China as the primary destination.
Those supply lines thread through the Strait of Hormuz, a narrow chokepoint that saw 20.5 million barrels per day of oil transit in 2024, according to the U.S. Energy Information Administration.
Behind the numbers: the players and the pinch points
A disruption at the Strait of Hormuz would not be a minor event. It would directly affect supply from Saudi Arabia, which produced 10.2 million barrels per day in 2024, Iraq at 4.5 million barrels per day, and the United Arab Emirates at 3.1 million barrels per day. These three countries alone account for a significant share of global production, and their crude moves almost exclusively through that waterway.
The Organization of the Petroleum Exporting Countries holds spare capacity of about 4 million barrels per day, mostly in Saudi Arabia. That buffer is designed to calm markets in moments of crisis, but it is not infinite.
If a major producer were taken offline, that spare capacity could be drawn down quickly. Meanwhile, the International Energy Agency estimates global oil demand at 103.5 million barrels per day in 2025. That figure represents the world’s appetite for crude, a number that has grown steadily even as renewable energy sources expand.
A market on edge
The March 31 jump was not driven by a single headline. It reflected a cumulative anxiety about supply security, geopolitical risk, and the fragility of the global energy system. Traders responded to a constellation of factors: tensions in the Middle East, the ongoing war in Ukraine, and the persistent question of how much spare capacity actually exists.
What matters for consumers is the ripple effect. When crude prices spike, the cost of gasoline, diesel, heating oil, and jet fuel tends to follow.
For industries that depend on transportation and logistics, every dollar increase in the price of oil cuts into margins. The 5.8% rise in Brent on March 31 was a reminder that the energy transition, however necessary for a clean planet, has not yet insulated the global economy from the old realities of geopolitics and supply chains.
What to watch next
In the months ahead, the focus will remain on the Strait of Hormuz and the producers that depend on it. Any escalation in regional tensions could trigger another sharp move. The spare capacity held by OPEC, particularly Saudi Arabia, will be tested if supply is disrupted.
The data from the EIA and IEA will continue to shape expectations. And for the families and businesses that feel the impact at the petrol pump and in the cost of goods, the question is not whether the market will move again, but when.
