Stocks and oil are sliding

US stocks are trading lower on Friday at the end of what's been the first full week of volatile trading since the aftermath of the UK referendum in June.

At 10:20 a.m. ET, the Dow was down 101 points (0.565%), the S&P 500 was down 14 points (0.66%) and the Nasdaq was down 21 points (0.41%).

The energy and financials sectors of the S&P 500 led declines in early trading. West Texas Intermediate crude oil futures were also lower, sliding below $43 per barrel. The contract for October delivery was down 2% to $42.86 in New York.

Earlier this week, the International Energy Agency cut its forecast for oil demand in 2017 and said the market would remain oversupplied for longer than it expected.

Deutsche Bank's shares listed in the US tanked 9% after the firm confirmed overnight that the US is seeking a $14 settlement over mortgage-backed security sales.

Treasurys were higher amid the sell-off in stocks. The benchmark 10-year yield was down by less than one basis point to 1.7%.

In economic data, consumer prices jumped more than expected in August, led by a jump in shelter and medical costs. And, the preliminary University of Michigan consumer sentiment index for September was unchanged at 89.8, as survey respondents lost confidence in their income prospects and buying plans.