At 9:33 a.m. ET, the Dow is down 104 points (-0.58%), the S&P 500 is down 10 points (-0.5%) and the Nasdaq is down 10 points (-0.2%).
The two big earnings reports came from McDonald's and General Electric. McDonald's reported stronger-than-expected sales growth after it revamped its all-day breakfast menu and kept customers interested in the offering. However, General Electric cut its revenue forecast, citing slow growth in the oil and gas business.
McDonald's shares gained 4%, while General Electric fell 2%.
Other major movers included Twilio, shares of which fell 7% after the company priced its follow-on offering below Thursday's closing price. Advanced Micro Devices fell 4% after the semiconductor company forecast a sales decline for the fourth quarter.
The economic-data calendar is light, with Markit's preliminary US manufacturing report for October due at 9:45 a.m. ET. It's expiry Friday for some stock-options traders.