Near 8:45 a.m. ET, Dow futures were down 56 points, S&P 500 were down 7 points, and Nasdaq futures were down 21 points.
On Thursday, stocks rallied in the final minutes of trading and closed slightly higher, with the Dow closing up 76 points. Deutsche Bank's Jim Reid noted that volume on the S&P 500 was lighter than usual, and the late-day rally was supported by tech stocks.
But again, the market action reflected the volatility and uncertainty that's plagued the stock market of late, and ahead of the Federal Reserve's interest rate announcement next week.
This is something that Fundstrat's Tom Lee highlights in his note to clients today. "Indecision and uncertainty", as well as a lack of confidence, characterize the sentiment of stock investors at the moment, he wrote.
There's a big new call on crude oil this morning: Goldman sees prices falling near $20 per barrel, and expects the oversupply in the oil market to persist into 2016.
West Texas Intermediate crude futures fell more than 3% to as low as $44.53 per barrel in New York on Friday morning.
In economic data, we learned that producer prices were flat in August. The Producer Price Index (PPI) for final demand was flat month-on-month, and fell 0.8% year-on-year.
And later this morning, the University of Michigan's consumer confidence report is expected to reflect the recent stock market plunge, according to Pantheon Macroeconomics' Ian Shepherdson.