American consumers tightened their purse strings unexpectedly last month, breaking a seven-month winning streak, data showed, spending less online and on groceries and other household goods.
The report raised questions about the US consumer, a pillar of the American and global economy.
Analysts also pointed to fresh doubts about whether revived efforts between British leader Boris Johnson and European Union officials will yield an agreement that can win support in Britain.
About 15 minutes into trading, the Dow Jones Industrial Average was down 0.1 percent at 27,007.60.
The broad-based S&P 500 dipped 0.2 percent to 2,991.02, while the tech-rich Nasdaq Composite Index fell 0.3 percent to 8,122.87.
Major US indices rose about one percent on Tuesday following a batch of mostly good earnings reports from JPMorgan Chase, Johnson & Johnson and others.
On Wednesday, Bank of America jumped 3.2 percent after reporting better-than-expected results on higher profits in consumer banking and most other divisions.
United Airlines gained 1.3 percent as it lifted its full-year profit targets on strong consumer demand.