Wall Street stocks dipped early Monday ahead of data later in the week on US consumer sentiment, pricing and manufacturing industry performance.
After about a month of largely unbroken upward movement, analysts have warned equities are poised for a potential pullback.
Countering that has been what market watchers call investor "fear of missing out" on future gains.
About 15 minutes into trading, the Dow Jones Industrial Average was down 0.1 percent at 35,340.74.
The broad-based S&P 500 dipped 0.2 percent to 4,548.97, while the tech-rich Nasdaq Composite index dropped 0.2 percent to 14,226.00.
This week's calendar includes the Conference Board's reading of consumer confidence, the Institute for Supply Management's rating of manufacturing industry health and US data on consumer prices, income and consumption.
Other crucial data, including the November jobs report and the consumer price index report on inflation, will come later in December.