
Trading above $100 per barrel on Friday, US benchmark West Texas Intermediate (WTI) is on course to gain more than 10% over the past three weeks. Oil has extended its rally following reports of a growing number of incidents involving vessels trying to pass through the crucial Strait of Hormuz this week, alongside renewed attacks on Saudi oilfields by the Iran-backed Houthis.

With Iranian forces tightening their control over the vital Strait of Hormuz corridor, the risk of supply disruptions from Gulf countries has returned to the fore. The navy of the Iranian Islamic Revolutionary Guard Corps (IRGC) said four additional tankers had been struck while conducting “illegal” oil transfers. Another three hit mines as they attempted to pass through the waterway.
At the same time, Yemen’s Houthi militias are stepping up strikes on targets in Saudi Arabia. Attacks earlier this week on Aramco’s Shaybah Oilfield and Dammam airport left four people dead and eight others injured.
As the conflict between the US and Israel and Iran nears its eighth month, there is still no clear prospect of an end. Citing US officials, the New York Times reported on Thursday that the US and Israel might be preparing a fresh round of coordinated strikes after November’s midterm elections.
In response, the IRGC warned that additional strikes on Iranian territory would lead Tehran to adopt an offensive strategy and invade neighbouring countries. Such a move would spread the conflict further across the region and put additional pressure on crude oil flows.
Traded internationally, WTI Oil is a grade of crude whose initials stand for West Texas Intermediate. Alongside Brent and Dubai Crude, it is one of the three principal types. Its relatively low gravity and sulphur content account for its descriptions as “light” and “sweet”, respectively. WTI is regarded as a high-quality oil that is straightforward to refine. Produced in the United States, it is distributed through the Cushing hub, known as “The Pipeline Crossroads of the World”. WTI serves as an oil market benchmark, with its price regularly cited by the media.
Supply and demand determine WTI Oil prices above all else, as they do for other assets. Stronger global economic growth can therefore lift demand, while weaker growth can have the reverse effect. Supply disruptions caused by political instability, wars or sanctions can also affect prices. Another significant influence is the production policy of OPEC, a group of major oil-producing countries. Because oil is traded predominantly in US Dollars, the currency’s value also affects WTI Crude Oil prices: a weaker US Dollar can make oil more affordable, while a stronger one can do the opposite.
WTI Oil prices respond to the weekly oil inventory reports issued by the American Petroleum Institute (API) and the Energy Information Agency (EIA). Inventory movements reflect shifts in the balance between supply and demand. A fall in stocks can signal stronger demand and lift oil prices, whereas rising inventories can point to greater supply and weigh on prices. The API releases its report every Tuesday, followed by the EIA the next day. The two sets of figures tend to be similar, coming within 1% of one another 75% of the time. As the EIA is a government agency, its data is regarded as more reliable.
At meetings held twice a year, the 12 oil-producing nations in OPEC (Organization of the Petroleum Exporting Countries) jointly set production quotas for member countries. These decisions frequently affect WTI Oil prices. A reduction in quotas can constrain supply and drive oil prices higher; an increase in production has the reverse effect. The wider OPEC+ group brings together OPEC and ten additional non-OPEC members, most notably Russia.