Crude Oil Prices Continue to Slide

"Rising products inventories, a depressed [refinery] crack market and a widening contango in the front of crude oil's forward curve ... underscore the weak fundamental state of the market," wrote Stephen Schork, an analyst and publisher of The Schork Report, in a research note.

"Whether bears are able to take out [oil's] technical support remains to be seen, but one thing is for sure: the fundamental ducks are lining up. With each passing week, it gets harder for the bulls to spin this market," Schork added.

Meanwhile, energy stocks were suffering. Among the integrateds, ConocoPhillips (COP Quote) was down 0.4% at $82.89, Chevron (CVX Quote) was losing 0.9% at $85.66, and Exxon Mobil (XOM Quote) was 0.6% lower at $80.32.

In the exploration and production space, Apache(APA Quote) was falling 4.1% at $109.78, Chesapeake Energy (CHK Quote) was down 7.1% at $52.60, Cabot Oil & Gas (COG Quote) was more than 9% lower at $50.92, and XTO Energy (XTO Quote) was sliding 6.8% to $53.98.

The U.S. Oil(USO Quote), an exchange-traded fund that closely tracks the performance of near-month WTI contracts on the Nymex, was declining 2.9% at $106.16.