Oil prices moved higher on Wednesday, with Brent climbing above $100 per barrel for the first time since July and WTI gaining more than $2 per barrel to around $95 per barrel. Brent has now climbed 25% since early August, highlighting how quickly prices have moved higher as concerns grow over supply availability and the possibility that current disruptions could persist longer than expected.

The focus now is on how much pressure the market can absorb if disruptions continue. Geopolitical risks remain elevated, and diesel supplies are tight, while production, inventories, and alternative trade flows are helping limit the impact. A longer-lasting disruption, however, could keep both crude and refined product prices elevated.

U.S. inventory data is also supporting WTI. The latest Energy Information Administration (EIA) data showed commercial crude inventories falling by 4.5 million barrels to 424.5 million barrels for the week ending August 28. Cushing, Oklahoma inventories rose only 80,000 barrels to 22.5 million barrels, leaving overall domestic crude supplies tighter despite the small increase at the key WTI pricing hub.

Middle East Disruptions Keep Crude Markets Bullish

The latest increase follows renewed attacks across the Middle East. Iran-backed Houthis attacked Saudi energy facilities this week, setting oil installations ablaze and increasing concerns that disruptions could spread to additional infrastructure and shipping routes.

The Strait of Hormuz remains at the center of the supply outlook. Reuters reported roughly 8-9 Mbpd moved through the Strait during the week before fighting resumed on August 30, but more recent flows have fallen below 2 Mbpd. The Red Sea has served as an important alternative route, making attacks on Saudi infrastructure and renewed Houthi activity another concern for global crude movements.

While the supply disruption has supported prices, the market's response may ultimately determine whether Brent remains above $100 for an extended period. Producers outside the Middle East, including the United States, Canada and Guyana, have increased production as regional exports remain constrained. Additional production, rerouted cargoes and some demand destruction from higher prices could help limit further upside. Continued disruptions through Hormuz and the Red Sea, however, would keep crude conditions bullish and increase pressure on global inventories.

Global Inventories Provide a Buffer

Whether prices remain elevated may depend as much on available inventories as the disruption itself. The United States has relied heavily on its Strategic Petroleum Reserve (SPR) in recent years, leaving fewer emergency barrels available compared with earlier periods of market stress.

The International Energy Agency (IEA) announced a 400-million-barrel emergency stock release in March, with roughly three-quarters of that volume already released. Total global inventories, including commercial stocks, government reserves, Chinese inventories and oil on the water, remain more comfortable than U.S. emergency inventories alone suggest.

However, not all of those barrels are readily available. Some supplies are already in transit or committed to buyers, while inventories in countries such as China remain less transparent. If disruptions in the Middle East continue, the accessibility of those inventories could become just as important as the total volume available.

Diesel Markets Remain Tight

Approximately 10 Mbpd of oil exports remain missing because of the Iran conflict, according to Vortexa estimates cited by Reuters. Increased production elsewhere has replaced some of those barrels, highlighting the market's ability to adapt. However, prolonged disruptions would continue testing global inventories, alternative supply routes and spare production capacity.

For fuel buyers, diesel remains a particular concern. Refined product markets remain tighter than crude markets as reduced exports from the Middle East and Russia combine with constrained refinery throughput in parts of Asia. Reuters says European diesel futures were trading near $199/bbl on Wednesday, while diesel refining margins reached $78.90/bbl on September 1 compared with an average near $21/bbl in 2025.

While Brent crossing $100 per barrel is an important market milestone, diesel fundamentals may be more consequential for fuel buyers. Elevated futures prices and exceptionally strong refining margins point to continued pressure in the refined product market, increasing the potential for higher fuel costs even beyond movements in crude prices.