The gap between Brent and West Texas Intermediate (WTI) crude benchmarks widened to nearly $9 a barrel on Thursday, driven by President Donald Trump’s comments on restricting U.S. diesel exports.

On Thursday, Brent stood at $100.88 and WTI at $91.89. This divergence is significantly wider than the typical $2 to $5 range. The spread reached its widest close since March at $12.68 on September 28.

Market reaction diverges

The widening gap stems from asymmetric price movements rather than a general market rally. Between September 18 and September 28, Brent gained $1.41 per barrel, while WTI fell $7.70. This contrasts with March, when both benchmarks rose due to Strait of Hormuz tensions, with Brent climbing faster.

Exchange-traded funds tracking these benchmarks reflect the split. United States Oil Fund LP (NYSE: USO), which tracks WTI futures, fell 5.3% between September 18 and September 30 closes. United States Brent Oil Fund LP (NYSE: BNO) slipped only 0.8%.

Policy uncertainty drives volatility

U.S. highway diesel prices hit a record $6.53 a gallon in late September, up 42.6% since July 10. On September 22, Trump stated, "Let's not send out the diesel. We make a lot of diesel." Although the White House later denied reports of a prepared 90-day export ban, Trump told Fox News on Sunday that the administration is "thinking about it very seriously."

Market participants are pricing in the risk of reduced U.S. refinery runs. Standard Chartered analyst Emily Ashford noted the market is pricing "the risk of a not-immaterial cut to U.S. refinery runs." StoneX analyst David Scutt said this implies "weaker refinery demand for WTI relative to Brent."

What the numbers show

The data reveals a structural disconnect between global supply risks and domestic policy impacts. While Brent reflects global seaborne supply constraints, WTI is increasingly decoupled due to specific U.S. downstream concerns. The $7.70 drop in WTI against a $1.41 rise in Brent indicates that traders view potential export bans as a direct threat to U.S. refiner margins and crude intake, rather than a global supply shock. Polymarket odds for a ban announcement by October 31 fell to 12% from 22% on September 24, suggesting some cooling of immediate fears despite the persistent price spread.

Chinese refiners have suspended October fuel exports to bolster domestic inventory levels. The move includes the cancellation of scheduled cargoes by major state-owned entities such as PetroChina.

Export suspension details

The decision affects multiple refining hubs across China. Sources indicate that the primary objective is to ensure adequate domestic supply before the peak winter demand season. This action follows a pattern of regulatory adjustments aimed at stabilizing local energy markets.

Impact on global supply

The suspension of export quotas and the cancellation of already booked cargoes create uncertainty in the Asian fuel market. Traders are monitoring the situation for potential ripple effects on regional refining margins and spot prices.

This development highlights the ongoing tension between domestic energy security priorities and international trade commitments for Chinese energy majors.