Oil exchange traded funds have followed crude futures lower this week as they back away from $100 a barrel on rising supplies and worries U.S. leaders won’t reach a compromise on the debt ceiling.

U.S. crude stockpiles increased 2.3 million barrels to 354 million last week, reports Ben Sharples for Bloomberg.

“You’ve got continued concerns with demand growth in the U.S.,” remarked Ben Westmore, minerals and energy economist at National Australia Bank Ltd. “Overlay that with the stocks report and it weighs on oil.”

In oil stocks, ConocoPhillips’s (NYSE: COP) second-quarter profits plummeted 18% after losing income from its former holdings in Russia, reports Isabel Ordonez for The Wall Street Journal.

Nevertheless, the company showed earnings of $17.09 per barrel of oil during the second quarter, almost double year-over-year, on high crude oil prices, reports Steve Gelsi for MarketWatch. ConocoPhillips is dumping its holdings on low quality oil fields and will focus on liquid-rich plays in the Gulf of Mexico and elsewhere, which the company believes will help set up more profitable returns in the coming months.

On Thursday, Exxon Mobil (NYSE: XOM) said its second-quarter profit rose 41% from the year-ago period.