Well-supplied markets and weakening demand for crude concern American drillers.

Global crude oil prices are now lower than they were before Israel attacked Iran earlier this month. A price spike did occur, but it was short-lived — unlike oil crises of the past.

The U.S. crude oil price benchmark, West Texas Intermediate, fell 8% to less than $68 a barrel, the lowest level since last week. The global Brent crude price benchmark likewise fell about 8%. Major stock indexes ended the day in positive territory.