Wall Street opened with little enthusiasm on Friday as stock traders digest the implications of Washington's continued failure to agree on a new stimulus package to bolster the battered US economy.
About 35 minutes after the open, the benchmark Dow Jones Industrial Average was down 0.3% to 27 822.74.
The broad-based S&P 500 dipped 0.1% to 3 355.10, while the tech-rich Nasdaq was up 0.3% to 10 938.38.
After a buoyant August, stocks have been under pressure for most of September given doubts about whether lofty valuations are justified.
Congress and the White House remain deadlocked over additional spending to aid businesses and households despite tens of millions of job losses caused by the world's worst coronavirus pandemic.
Tech stocks in particular have had rough trading sessions in recently after the Nasdaq posted multiple records last month.
Apple was trading 0.8% lower, Amazon was down 0.2%, and Google-parent Alphabet slipped 0.1%.
Before trading began, Commerce Secretary Wilbur Ross said the US would ban on downloads or updates of popular video sharing app TikTok starting Sunday night following Washington's threat to crack down on the app over national security concerns unless it could find a buyer in the United States.
Oracle, which is in talks to become the app's US partner, fell 0.8%.