Energy sector-related exchange traded funds were among the best performers on Friday, despite the steep pullback in crude oil prices after President Donald Trump tested positive for Covid-19 and a rise in global crude output.

On Friday, the VanEck Vectors Oil Service ETF (NYSEArca: OIH) gained 3.1% and iShares U.S. Oil Equipment & Services ETF (NYSEArca: IEZ) increased 2.9%. Meanwhile, the broader Energy Select Sector SPDR (NYSEArca: XLE), the largest equity-based energy exchange traded fund, was 1.5% higher.

Meanwhile, the United States Oil Fund (NYSEArca: USO), which tracks West Texas Intermediate crude oil futures, and the United States Brent Oil Fund (NYSEArca: BNO), which tracks Brent crude oil futures, were 3.8% and 3.7% lower, respectively, on Friday while WTI crude oil futures were down 4.2% to $37.1 per barrel and Brent crude declined 3.9% to $39.3 per barrel.

The Brent and WTI crude benchmarks were both headed toward a second consecutive week of losses, with the latest pullback triggered by the uncertainty over Trump’s health, a weak unemployment report and rising supply out of major world oil producers, Reuters reports.

“It’s been a rough week – and now the president’s diagnosis sends a shudder through markets,” John Kilduff, partner at Again Capital, told Reuters. “The COVID-19 pandemic has weighed more on the oil market than any other asset class. This is a worst-case scenario for the oil market.”

Looking ahead, some warn that crude oil markets may continue to struggle due to dampened demand.

“If anything, they’re vulnerable to falling into the low $30s. The oil market is taking Covid the hardest of all of the asset classes out there,” John Kilduff, partner with Again Capital, told CNBC. “Demand is just not coming back, especially for jet fuel.”

The Organization of Petroleum Exporting Countries also recently cut its near-term demand outlook, projecting demand to average 90.2 million barrels a day in 2020, or down 400,000 barrels a day from its last estimates and a drop of 9.5 million barrels a day year-over-year. OPEC also saw its production rise in September by 160,000 barrels per day from a month earlier, which may be attributed to increased supply from Libya and Iran.

“There are still these serious headwinds for oil in terms of the macro outlook,” Helima Croft, managing director and head of global commodities strategy at RBC Capital Markets, told CNBC. “OPEC is very focused on compliance. It’s just a question to me of how much more can you get out of these producers in terms of compliance.”

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